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DMAG
04-04-2005, 10:01 PM
Installation of a MDS “ON” Indicator Light



written by Magnuman



Added 10/23/06: New, updated PDF version by IT Rider can be downloaded HERE (http://lxforums.com/articles/MDS_light.pdf).



The following is a “How to” for the addition of a Multi-Displacement System (MDS) “ON” indicator light for the 2005 MDS equipped Hemi engines installed in the Dodge Magnum RT.



This may also work on the Chrysler 300C, but the installation in that vehicle has not been verified. This document is intended for reference only, and is merely a step-by-step of how the author installed this modification on his own vehicle. Anyone using this document as a guide to install this modification is doing so solely at their own risk. This installer should have, as a minimum, an intermediate understanding of automotive electrical principals and systems, electrical circuitry, wire routing and termination, insulation requirements and circuit protection. The author accepts no responsibility for errors, omissions, or any other problems or damage that may be caused by this installation.


The purpose of this modification is to provide a method (lighted switch in “on” position) of monitoring when the MDS is active. Turning the switch off will stop the light from coming on and cease monitoring of the MDS. It will not affect the operation of the MDS. It is accomplished by connecting the lighted switch to the power wire for the No. 4 cylinder MDS activation solenoid. Connection is made to the wire leading to Pin 28 of plug C1 of the Powertrain Control Module (PCM).


Parts Used


All parts were obtained from local auto parts store.






1 ea.Illuminated rocker switch (any color)


1 ea. Plastic rocker switch mount bracket


2 ea. No. 8 X ½ inch, pan head sheet metal screws (to mount switch mount bracket)


10 ft.24 gauge or larger, 2 conductor multi-strand wire
--each wire should be identifiable, i.e. two different colors.
--two color speaker wire works great



6 in. 18 gauge multi-strand wire (Should be this size to tie into 18 gauge MDS power wire on PCM)


5 ea.Solderless fully insulated wire connectors to match wire size(s)


2 ea. Push on style to match connections on back of rocker switch


1 ea. Female push plug barrel style connector (to be used on 6 inch wire)


1 ea. Male push plug barrel style connector (for power wire to switch)


1 ea. Connector with ¼ inch hole or “open” horseshoe type (for switch ground at PCM)


1 ea. 18 gauge saddle type wire splice (the type used for hooking up trailer wiring) --used to tie into MDS power wire on PCM


4 ea. 8-10 inch nylon ties


1 roll Electrical Tape


Tools used






--Common screwdriver


--No. 2 phillips head screwdriver


--8-10 inch long small common screwdriver (used only to feed wire thru firewall)


--Set of metric end, box or socket wrenches


--Exacto knife (preferred) or single edged razor blade


--Wire cutters


--Wire strippers


--Solderless terminal crimping tool


--Standard or channelock pliers (used only to crimp closed saddle splice)


--Drill motor


--.110 (approximate) drill bit (for drilling mount bracket holes)


--Multimeter (handy but not mandatory)


--18-24 inch Test lead with alligator clips on each end (handy but not mandatory)
Be sure ignition switch is off. Disconnect the battery, for insurance, if in doubt. Note that if battery is disconnected, resetting of some vehicle functions may be required.




Preparation (under hood)


1. Remove plastic PCM cover held on by two push lock fasteners. Use common screwdriver to pull up on center of fasteners. The PCM is located in the right front fender well near the firewall.

2. Remove the PCM. Held on by one bolt. Let it sit on mount brace.

3. Loosen or remove (depending on type of ¼ inch ground wire connector you have) PCM mount bracket bolt nearest the C1 plug on the PCM.

4. Unplug top (C1) plug on PCM only.

PCM_C1_Pinout (http://lxforums.com/images/How_To/mds/PCM_C1_Pinout.jpg)
4. Using an exacto knife or single edge razor blade carefully slice the electrical tape covering the wires on plug C1 from the plug to the junction with other wires (about 2 inches), being careful not to damage any of the wires. I used an exacto knife and slid it under the tape and cut away from the wires.

5. Gently peel the tape back, but do not remove it. Wires from plug should now be exposed.

6. Locate and isolate the 18 gauge brown with light blue striped wire. This is the No. 4 cylinder MDS activation solenoid power wire. Power from this wire will be used to turn on illuminated switch.

*************************************************
EDIT (4-8-05):

There is more than one brown/light blue striped wire on plug C1 of the PCM.

The brown/light blue wire we are concerned with is the one that goes to Pin 28, the MDS solenoid for the No. 4 cylinder. (The other brown/light blue striped wire goes Pin 4 and is connected to the injector control for the No. 8 cylinder. There is also a plain brown wire with no stripe going to pin 33, which is the No. 2/2 oxygen sensor signal lead.)

Please refer to the diagram of the C1 plug below and the Plug pinout chart below to ensure you are splicing the correct wire!

C1 Plug (http://lxforums.com/images/How_To/mds/PCM_C1_Plug.jpg)
C1 Plug Pinouts (http://lxforums.com/images/How_To/mds/PCM_C1_Pinout.jpg)
*************************************************


7. From the driver’s side under the hood, locate the small cable and grommet that goes through the firewall. It is located about 10-12 inches above and to the outside (right) of the steering linkage. It’s the only one there, so shouldn’t be too hard to find.

8. Pull the soft center of the grommet away from the firewall (toward front of car). Later we’ll feed the wire through this grommet.




http://www.lxforums.com/images/How_To/mds/pcm.jpg



http://www.lxforums.com/images/How_To/mds/pcm2.jpg


Preparation (inside the car on driver’s side)

1. With door open remove trim strip (approx. 12X2 inch) on door side of lower dash panel. Gently slide a common screwdriver under the strip and pry the clips loose. I think there is one at each end. This will expose one (1) lower panel mount screw.

2. Remove mount screw and one (1) other located at the bottom of the panel to the left of the steering column.

3. Gently pull the top of the panel from right to left toward the back of the car. You can get hold right under the steering column to start. The panel is held in place by about four snap clips similar to those on trim strip. Just let panel lay on floor.

4. Remove shiny metal panel under the steering column, held on by four metric bolts.

5. Using the switch mount as a template, locate, mark and drill mounting holes. I mounted mine under the ignition key. There is a little recessed shelf separating upper dash from the lower panel that works great. This location is easily visible to the driver, relatively inconspicuous, and does not cause excessive glare at night. Do Not mount switch bracket at this time.

DMAG
04-04-2005, 10:01 PM
Installation and Testing


1. Using the saddle splice, connect and securely lock the six inch 18 gauge wire and the previously isolated 18 gauge brown/light blue striped wire on plug C1 of the PCM.

2. Strip and securely crimp the female barrel style push plug to the other end of the six inch 18 gauge wire.

3. Slip the original electrical tape cover back over the wires and, using electrical tape, securely re-tape (leaving just the six inch “pigtail” exposed) to look like the original installation.

4. Strip and securely crimp the male barrel style push plug to one of the speaker wires, making note of wire color or identifying mark. This will be the power wire going to the lighted switch. Do not plug in at this time.

5. Strip and securely crimp the connector with the ¼ inch hole or open horseshoe to the other speaker wire.

This will be the ground wire going to the lighted switch.

6. Connect this wire to the previously loosened or removed mount bracket bolt on the PCM. Tighten mount bolt.

7. Route the wires behind the fire wall support brace (the one the PCM is mounted to) and secure with nylon ties. The nylon ties will slide between the brace and the plastic cover mounted to the top of the brace. The last nylon tie should be place directly over the cable/grommet area. The only thing that should be visible are the nylon ties.

8. Using electrical tape secure the free end of the wire to the small 8-10 inch common screwdriver starting about 2 inches back from screwdriver blade. Note: Leave a little tape pigtail so you can easily remove the tape after feeding through the firewall.

9. Push screwdriver and wire through the firewall grommet. This will require a little force to puncture the grommet. Push in far enough to grasp wire from inside the car.

10. From inside the car under the dash, locate and remove tape from screwdriver. Pull remaining wire into car.

11. From under the hood, remove the screwdriver and push the soft center of the grommet back in place.

12. Route wire to the area where the switch is going to be mounted, being careful not to interfere with any moving parts under the dash. I routed over existing wire looms away from pedal/steering mechanisms.

13. Reinstall shiny metal panel.

14. Reinstall lower dash panel, making sure to hold wire between upper dash and lower panel right behind where the switch mount is going to be mounted. Reinstall trim strip.

15. Mount the switch mount using the previously drilled holes and two No. 8 sheet metal screws.

16. Route the wire through the hole in the switch mount.

17. Strip and securely crimp both wires using the two connectors that fit the back of the switch.

18. Connect both wires to their correct terminals. My lighted switch had 3 terminals: Supply Volts, On Acc., and Earth Ground. The previously identified power lead gets connected to the Supply Volts terminal, and the ground wire gets connected to the Earth Ground terminal. Do not hook anything to the center On Acc. Terminal.

19. Lightly and carefully pull the lower panel outward and push the excess wire back behind the panel. Secure the switch in the mount.

20. If battery was disconnected, reconnect it now. Reset various vehicle functions, as needed/required.

21. If you have a test lead, connect one end to the male barrel style push plug and the other end to the red “positive” terminal on the Forward Control Module (FCM) located in front of where you are working. Go in the car and activate the switch. The light should come on. Turn switch off and the light should go out.

22. Disconnect test lead and connect the male barrel style push plug to the female barrel style push plug on the exposed pigtail at the PCM.

23. Reinstall the PCM and its cover.

24. Go for a ride and try it out.


http://lxforums.com/images/How_To/mds/switch.jpg

Dupie24
04-07-2005, 11:48 PM
I have a question. Does the pcm provide power to the mds solenoid or provide a ground? Ususally high current output devices (over a few amps) are ground side switched. Is the mds solenoid normally off or on? If this installation actually works and I'm sure you've tested it, the pcm must be providing power to the solenoid to activate mds which seems odd to me, but I've seen chrysler do some wierd things. When they have hot switched circuits in the past there were a lot of pcm failures. They probably got the design bugs out of power switching circuits or at least I hope so.

Fred
04-08-2005, 01:48 PM
Well by powering up the solenoid to enable mds operation, this leaves the car running on all 8 if there's a power issue.

redinorange
04-08-2005, 02:00 PM
While I appreciate the effort that went into figuring out this modification, I have to ask; other than satisfying a passing curiosity, what is the long term use of this?

DMAG
04-08-2005, 02:33 PM
When I get my HEMI, I plan on doing this but with an LED in the instrument cluster.

magnuman
04-08-2005, 05:36 PM
Dupie24,
The lead in question does indeed provide power to the MDS solenoid on the No. 4 cylinder. It is not the ground. The MDS is normally in the off position and the solenoid, along with the solenoids for the other 3 MDS cylinders (1, 7, and 6) activates the system. The PCM provides the power, apparently once all preprogrammed parameters are satisfied, and shuts it off, apparently when any of the parameters become out of range. Most small instrument/indicator type lights consume very little power and I have not had any problems with Malfunction Indicator Lights (MIL) or fuses blowing. I've been running the system for about two weeks now, and am still trying to figure out the parameters that have to be met to make the MDS work. It is apparently quite a complex set of parameters, too. So far I think, at least the following are involved: engine coolant temperature, engine oil pressure, engine manifold pressure (vacuum), speed, gear selector position and actual gear the trans. is in, and throttle position.

magnuman
04-08-2005, 05:37 PM
Fred,
I believe you are correct in your statement about power problems would cause the system to revert to the 8 cylinder mode and render the MDS inoperative.

magnuman
04-08-2005, 05:48 PM
redinorange,
Curiosity is indeed one of the motivators for this mod. I've read somewhere that DCX initially had a light installed but removed it because it was coming on and off too frequently. They apparently thought it would more of a distraction than a help. Since I am starting to figure out what parameters must be met to make the MDS work, I have found that I can coax the MDS to come on when it normally wouldn't, especially below 30 mph and above 50 mph. My last tank of gas, mostly in town (not a lot of stop and go) with some rural driving, was 18.2 mpg. My normal in town mileage runs 15-18, depending on the amount of rural and stop and go traffic that is involved. With the price of fuel now, I'll take any increase in mileage I can get. The reason I used the lighted switch is that if I don't want to monitor it, I can simply turn it off. I do like to tinker and I thought, inquiring minds, like mine, might want to know. Maybe not the best rationale, but that was mine.

DMAG
04-08-2005, 07:58 PM
Please refer to the addition to this How To in the first post regarding the wire color in the C1 plug. (This refers to the correct wire since there are multiple wires that look alike...we want you splicing the correct one) :)

VIDEOBOB
04-09-2005, 03:15 AM
This is a cool mod, but has anyone figured out a way to manually overide the controls?
It would be cool if you could lock the system into either 4/8 mode when ever you wanted and keep it that way.
This might cause problems though.... the good folks at Dodge know what they are doing I suppose. But it would be nice to have the option if it were safe.
Sort of like the option to select gears with the "Auto-Stick".

RT4me
04-09-2005, 04:13 AM
This is a cool mod, but has anyone figured out a way to manually overide the controls?
It would be cool if you could lock the system into either 4/8 mode when ever you wanted and keep it that way.
This might cause problems though.... the good folks at Dodge know what they are doing I suppose. But it would be nice to have the option if it were safe.
Sort of like the option to select gears with the "Auto-Stick".


VBOB, I see what your saying, And I sure somebody will figure it out some day.
Although, I woulden't want to keep the car in 4 cyl. mode for to long. Unless say, hypotheticaly there was MDS on all 8 cyls. & the system could change from one bank 1,4,7,6 to the other bank 2,3,5,8.
I'm just a shady tree mechanic, but woulden't this cause uneven wear in the long run ?

just my .02

magnuman
04-14-2005, 11:12 PM
VIDEOBOB and RT4me,
A few of us are still working on this. Here's the thread:
http://www.dodgemagnumclub.com/board/showthread.php?t=11756
If you have any ideas, feel free to chime in. Knowledge is power. Thanks for the interest.

cdn2usa
05-16-2005, 06:55 AM
Great mode, did it this past weekend. Did not bother to run the light/switch inside for now. Bought a 12v red led at Radio Shack and mounted it just under the hood on the driver's side by the wiper arm.

da BoMM
05-16-2005, 07:04 AM
Bottom line:


How much (in parts) $$

How much time (to do the mod) ?

Thanks.

CLENOFF
05-16-2005, 05:34 PM
Maybe related, maybe not:

What's the significance of the boxed number 8 that appears a few spaces to the right of the PRND indicator on the dash (its probably two spaces over from the gear indicator that appears when you are using the autostick)? It only lights up as I turn the key prior to starting the car. When I first saw it, I thought it WAS an MDS indicator but I never see it on while the car is running...

Fred
05-17-2005, 11:41 AM
It shows the gear number when you're autosticking, until you hit it to 5th then it goes away.

magnuman
05-23-2005, 05:58 PM
BragonMyMag,
I don't remember exactly how much the parts were, but it is certainly no more than $25.00. I tried several different light/switch configurations and settled on the illuminated rocker switch, because it served two purposes....the light, and the capability to turn it off if I don't want to monitor (hasn't happened yet though). If you have any more questions, I'd be glad to help.

snickle
07-12-2005, 11:25 PM
I am planning on this mod soon. I will use a small led mounted in the dash and a hidden switch somewhere. I can't use the location in the KB, because that is where my radar detector head unit is.

Here is what I wil lprobably use:

http://www.thinkgeek.com/pcmods/cables/6ca5/

Should fit nice where the 300 trunk button is.

magnuman
08-15-2005, 01:47 PM
snickle,
Just read your post in the Knowledge Base on the illuminated rocker switch. I really like it. Where do you get them? Have you done the mod. yet? If so, how do you like it?

snickle
08-15-2005, 01:55 PM
I used this switch:

http://www.autobarn.net/pilplsw15.html

See this thread: http://www.lxforums.com/board/showthread.php?t=15229&page=2&pp=10

Works well.

GN_driver
09-08-2005, 11:15 PM
When I get my HEMI, I plan on doing this but with an LED in the instrument cluster.
You sure are a fountain of information for a newbie. Please don't stop.

Redfox0099
09-08-2005, 11:45 PM
You sure are a fountain of information for a newbie. Please don't stop.

Um, Dude, not to shoot your comments down again (the weak transmission comment in the "GSM Traction Control" Thread) but DMAG is a site Administrator with almost 4,000 posts. He is nowhere near a newbie but you seem to be. Look to the top right side of the posts and it says how many post they have made, just a friendly tip.

kra9235
12-30-2005, 03:30 PM
I would like to use the VTA led in the gas gauge as an MDS indicator. Does anyone know here the VTA light pin out is located. I'm not sure if it shows this in the shop manual, but I hope someone can help me find this info.

k

fnkychkn
12-30-2005, 06:42 PM
the VTA/SKREEM indicator lamp is driven by the CCN (cabin compartment node/cluster) according to messages received over the CAN bus. there is no dedicated circuit unless you can find it on the CCN circuit board.

BrilliantBlackHemi
12-30-2005, 07:51 PM
I thought that little RED LED would be good for MDS light too. I wonder if you could wire it in and maybe add a diode if neccesary to protect the theft system circuits. That would give it a purpose with the vehicle running and allow it's purpose to continue when it's locked up and armed. I'm not brave enough to pull it apart and investigate though.

wquiles
02-28-2006, 09:44 PM
Excellent little mod - thanks for sharing with the rest of us :)

Best part about reading this thread (and the links posted) is that I learned a little bit more about the MDS system ;)

Will

krwkenny
02-28-2006, 10:25 PM
I have exhaust cut-outs open right now and you can definitely hear the change from 8 to 4. It does change back and forth often with even the slightest pedal or load application. I don't know if the manual over-ride will work because the lifters also come into play. I'm not exactly sure how the whole thing works.

cdn2usa
03-20-2006, 12:46 PM
Let me insert my .02.

I opted to install the indicator on the exterior, under the hood lid to the left of the wiper.

http://www.lxforums.com/board/attachment.php?attachmentid=3072&stc=1

magnuman
03-20-2006, 12:56 PM
cdn2usa,
I like your installation. Sure beats routing the wires into the cabin. How does it work at night? Any glare or distraction? Did you install a switch so you can turn it off?

BobFam
03-20-2006, 03:34 PM
Let me insert my .02.

I opted to install the indicator on the exterior, under the hood lid to the left of the wiper.

http://www.lxforums.com/board/attachment.php?attachmentid=3072&stc=1

Exactly how did you mount the LED? Sounds neat! No need to mess around with the dash panels. I like it! Regards, Bob.

cdn2usa
03-20-2006, 04:51 PM
cdn2usa,
I like your installation. Sure beats routing the wires into the cabin. How does it work at night? Any glare or distraction? Did you install a switch so you can turn it off?

There is no problem at night, only during the day when the sun is shinning directly at the LED. But it is visible at all other times, because it's set-back in the darkness under the hood. I will try and get to Radio Shack and get the part # of the LED I used. I ran the wire from the passenger side to the driver's side through the hood support channel, there are holes on either end that line-up pretty close to where you want to end up. The trick is to fish the wire through the channel

http://www.lxforums.com/board/attachment.php?attachmentid=3074&stc=1

JimTurner
03-20-2006, 04:59 PM
For me (300C) the hood option was not an option. (Driver sits farther down).

I put mine here:

jimt

Electrofied
03-20-2006, 06:21 PM
I can hear when MDS activates via my exhaust tone and engine temp. My MDS will activate below 30MPH and all the way over 70MPH.

Whne it activate my TB spacer gives a little whistle and the exhaust tone changes dramtically. Once activated my engine temp drops from the 199-200+ down to 192-197 degree range.

E

Tabasco
04-02-2006, 08:32 PM
I just finished doing this mod and only ran into one issue/concern, when I went to "Test" as per the instructions, I'm not getting a light/12v from the wire by just turning the key to the "ON" position. I actually have to hit the road for a test before the light would come on. When it did, it was consistent with what I felt the MSD should be doing. I thought it might have been that it wasn't at operating temp when I first tried the test but I got the same result once I got back from the ride and after seeing the light work.

I double checked the wire connecting to Pin 28 on plug 1. Any ideas? I have a 2005 R/T.

Thanks for the mod.

magnuman
04-02-2006, 08:51 PM
Tabasco,
If you're referring to items 21-22 of the instructions, this requires an external test lead (12VDC) to check the function of the light. If you've already driven it, and everything works, you don't need to test it further. Sounds like you've got it going though. Generally, the MDS will not work until the engine temp. is at least 120> degrees. Since installing the SC Tuner, mine now begins coming on at 100 degrees...something it had never done before. With the SC it also comes on easier, stays on longer and the speed ranges for activation and operation have expanded. Sometimes it also stays active through a shift, which it never did before. The SC Tuner is a great mod., IMO. So far, my in town mileage average (first tank with SC) is up almost 3 mpg.

Tabasco
04-03-2006, 01:03 AM
Magnuman - Thanks. I guess I didn't read the steps right. I didn't get that I was just testing the lamp and not the setup as a whole. Now that I re-read it with your input, it makes perfect since and I honestly did that test anyway just out of installation habit. As for the SC Tuner... I have one on the way from Southern Hotrod and can't wait to see it and play with it. What program are you using to get the 3mpg bump? 87 oct or 92 oct?

Thanks, again.

ratman1648
04-07-2006, 12:28 AM
this LED works very nicely and can be seen even with the sun on it yet it isn't distracting at night
http://www.radioshack.com/product/index.jsp?productId=2062548&cp=2032058&f=Taxonomy%2FRSK%2F2032058&categoryId=2032058&kwCatId=2032058&kw=12v+led&parentPage=search

PRB45
04-19-2006, 09:43 PM
Magnuman, Thanks for great write up on how to install lighted switch to monitor MDS system cycle. Installed on 2006 Charger R/T( same color as your Magnum) over weekend in about 20 minutes, after I got parts, thanks to your detailed write up and pictures. I had the same reason as you for the hook up. Just wanted to know when and how it cycles. Thanks Again PRB45

magnuman
04-22-2006, 06:32 PM
PRB45,
You're welcome! A guy in town here has a midnight blue Charger RT, also. I really like the color on the Charger, plus it's no longer availible. Ought to make your ride worth more, as I am sure there aren't that many MB Chargers around. The light will also help you optimize your mileage too.

MPH RT
05-01-2006, 08:53 PM
One quick question, and sorry if the answer is buried in the instructions. Does the illuminated led indicate 4 or 8 cylinders are firing? Thanks in advance.

MPH RT

fnkychkn
05-01-2006, 10:09 PM
One quick question, and sorry if the answer is buried in the instructions. Does the illuminated led indicate 4 or 8 cylinders are firing? Thanks in advance.

MPH RTIIRC, the LED illuminates when in 4 cylinder mode.

gotahemi
06-03-2006, 10:38 PM
Thanks magnuman for a great write up! :thumbs_u: Installed one today and everything went great. I didn't even mess up the dash cutting the hole for the switch. I mounted it to the right and above the temp gauge. here's a pic.
4061

The light is green but just bright enough to be seen in the sun but hopefully not blinding at night.

I think they did not have an indicator stock because of how ridiculously little it is in 4 cylinder mode. If the gas is touched at all it goes back to 8! The big reason the 4 cylinder saves gas is that the throttle opening is larger in 4 cylinder mode reducing throttling losses but it seem that it doesn't let the 4 cylinder mode open the throttle much before it kicks back to 8. I wish it would let it hang in 4 more and keep out of the tiny throttle openings required with 340 hp on tap. It can't be using more than 50 hp before going back to 8 cylinders, seems like a waste, could be much better on gas if it was programmed better.

I bet in the '06 Rams it has to be almost going downhill before it engages 4 cylinder mode!

magnuman
06-06-2006, 11:35 PM
Gotahemi, you're welcome. How is it working for you, so far? I also use a ScanGauge to monitor other MDS/engine critical functions. You can monitor up to 4 items at a time. I monitor engine load, IAT sensor temp., timing, and engine coolant temp. If you have a Superchips Flashpaq Tuner, and set it to "raised shift points", the MDS works a whole bunch better in town. Works the same as before on the highway. I've gotten as high as 18.3 in town stop and go, and 33.5 on the highway at 60-70 mph. If you run the 91 tune, it cranks at least another 10 degrees of timing into the engine for all ranges.

gotahemi
06-14-2006, 11:08 PM
So far so good, got over 21mpg for the first time with it! Am learning how to keep the thing on more but it is very hard to know how much gas you can get away with when there is no feedback in the gas pedal. Kind of have to totally drive by the seat of your pants to tell if you are accelerating at all. It's fun to have it though, there are times when it should be on but isn't so a quick jab and let off will turn it on every time. I can also feel the MDS kicking out without looking at the light, still can't feel it going in though.

I was looking at the scan gauge II but noticed that it has a disclaimer about the MDS and mileage readings. How far off is it? I was looking around the dash and I think there is room to cut it in under the fuel gauge so it'll look clean. I'm really interested in it since I don't have the EVIC, and I love looking at mileage vs. anything to see how to improve.

thanks

RTPablo
06-15-2006, 11:30 PM
Just curious, what sounds are you hearing when the MDS kicks in and out? Not sure what to listen for. Have stock exhaust.

Pablo

quarky42
06-16-2006, 09:59 AM
It will be difficult to hear with the stock exhaust. I hear that if you remove the resonators it is a lot easier to hear... a sort of droning tone when MDS kicks on. With other exhaust systems it is easier to hear.

magnuman
06-16-2006, 12:35 PM
gotahemi, without the EVIC your best bet is the ScanGauge. I've emailed them and they still have not cracked the code for the fuel functions while in the MDS mode. The SG is still good for monitoring engine functions and viewing/clearing DTC's. Well worth it, IMO. If you take the resonators off, you should easily be able to hear the MDS kick in. I've got the Daytona suitcase muffler with the stock resonators and I can hear it and feel it kick in. The exhaust make a noticeable shift in pitch (sound).

McKinneyMagnum
06-16-2006, 02:07 PM
Thinks this MDS light is my next mod! I noticed on a Chevy Impala commercial that they have a 4cyl / 8cyl light in the instrument cluster. So, it would be cool if Dodge would do the same. Maybe make it an software upgrade to the EVIC system....if that's possible.

magnuman
06-16-2006, 08:23 PM
I've heard (Internet rumors) that DCX initially had a light for the MDS, but removed it because the continuous cycling caused a distraction for the driver. Mine is mounted low (below the key) and is not a problem, but at night it is still a little bright. I tried several lights before using the one that I used. I know several people have found better lights, but some of those are a little tough to see in daylight, but great at night. I rate mine as great in daytime, but slightly marginal at night.

gotahemi
06-16-2006, 10:59 PM
The mds kicking out is more like a feeling, like a torque converter locking or unlocking or the a/c clutch changing the loading on the engine creating a different feel and sound. It is a slight shudder usually.

I liked the up high location of the light so I don't have to look for it. I bought 3 switches, green, blue and red. I settled on the green because it was the least obnoxious when lit. Cutting it in went so well that if I have to add another switch i'll probably mount in the same area.

magnuman I'm really getting interested in the scangauge, I wish I had the EVIC but you can't always get when you want when going used. What I would really want it for is to track average speed or running time. The instant mileage is secondary to me. Is it able to be updated after purchase if they do figure it out? Do you know the status of the usb interface? That would be nice since it could be updated if they figure the mileage thing in mds out. Thanks for all your help and info!

magnuman
06-16-2006, 11:50 PM
Here are the functions of my early version ScanGauge:
1. Fuel System Loop Status (open or closed)
2. Intake Air Temperature
3. Water (coolant) Temperature
4. Fuel Pressure (our PCM does not report this)
5. Gallons/Liters per hour of fuel consumption
6. Ignition Timing
7. Engine Loading in %age format
8. Miles/Kilometers per Gallon (erroneous due to MDS)
a. Miles/Kilometers per Liter (same as above)
9. Miles/Kilometers per Hour
10. Manifold Absolute Pressure
11. Engine Revolutions per Minute
12. Throttle Position Setting
13. Battery Voltage
14. Scan/Clear Diagnostic Trouble Codes (DTC)
15. Trip Functions
a. Maximum Speed
b. Maximum Coolant Temperature
c. Maximum Engine RPM
d. Average Speed
e. Average Miles per Gallon (erroneous due to MDS)
f. Trip Miles
g. Trip Elapsed Time
h. Trip Fuel Used (probably erroneous due to MDS)
i. Fuel used since last fillup. (same as above)
j. Fuel Remaining (same as above)
k. Distance Driven since last fillup
l. Distance remaining until tank empty (same as above)
m. Time driven since last fillup
n. Time remaining before tank empty (same as above)

I haven't messed with any of the trip/mileage/fuel functions, and haven't verified their accuracy, but I am sure the mileage/trip functions are as accurate as the speedometer/odometer on the car. I also am not sure if the new ScanGauge has more or less functions, but I do know it is significantly smaller than mine. They say they can do a limited upgrade to my unit. I don't know what all would be upgraded except for coming on when the ignition is turned on. I have to push the "Home" button each time to turn mine on. Hope this helps.

Axeman
07-18-2006, 03:19 PM
Magnuman;
You're reasoning is solid. A simple solution to improving fuel efficiency can't ever hurt. Besides, another light to entertain is always cool.

gotahemi
07-19-2006, 11:23 PM
Have had the light in now for a little over a month. It still completely baffles me why it stays on 8 cylinders some times, but you can get it to kick in more often with practice. One observation, in the AWD, on a foggy day with a/c on and anything over 70mph, it hardly ever comes on.

Now for the good news! The car averaged 16.8 mpg before the light install, 5600 miles mixed driving. In the 2700 since the light install it has averaged 18.2mpg. Has the driving been different, most likely, but the minimum mpg's are in the 16's instead of low 15's, and the highway tanks aren't much better so it seems to make the most difference in town.

There are times when that the MDS won't come on as often on the highway and it shows up in the mileage. The above mention foggy day ended up average just under 20 when the last similar tank that had plenty of MDS active time was over 21. So it obviously makes a difference.

Now we'll see what the Borla 112 does to mpg! Then superchips later on!

quarky42
07-20-2006, 11:16 AM
For me, Superchips 91 octane tune was good for more than a few MPG for me on the highway when I kept my foot out of it.

oldschool
08-07-2006, 09:49 PM
Another way I notice MDS is kind of obvious although no one has stated it yet. Since it usually only comes on after a "cruising" speed has been established I notice it right at the tach. They dip down maybe 500 or so rpm's. Anyone else notice this?

oldschool

fnkychkn
08-07-2006, 09:57 PM
Another way I notice MDS is kind of obvious although no one has stated it yet. Since it usually only comes on after a "cruising" speed has been established I notice it right at the tach. They dip down maybe 500 or so rpm's. Anyone else notice this?

oldschoolare you sure that's not the torque converter locking up?

joseph
08-30-2006, 05:58 AM
I'd like to do that mod, but the instructions are not the best in the world,
any way you can repost with step by step pictures along with the instructions?
How did that speaker wire magically appeared and how did you connect it?
I'm confused, too many steps missing.

dewey cheatham
08-30-2006, 11:51 AM
I hooked up the MDS light on my Charger Hemi. I used a 12 vold LED, no switch. When I first started it up, it was missing on at least one cylinder and the light was on at idle. I disconnected it right away. Now the engine light is on all the time!, but it runs fine. I used the brown with blue stripe wire and ground. Can the color code be different on my Hemi? HELP! How do I clear the codes and turn off the light? Why the heck didn't this work?

quarky42
08-30-2006, 12:18 PM
" The brown/light blue wire we are concerned with is the one that goes to Pin 28, the MDS solenoid for the No. 4 cylinder. (The other brown/light blue striped wire goes Pin 4 and is connected to the injector control for the No. 8 cylinder. There is also a plain brown wire with no stripe going to pin 33, which is the No. 2/2 oxygen sensor signal lead.)"

Could you have connected it to the wrong wire? Can you make sure it is on the right wire. The positive leg of the LED should be connected to the wire that goes into Pin 28.

If you connected to Pin 8 by accident you could have been missing a cylinder.

Did you connect the LED in the right polarity? This means that one leg of the LED is positive and the other leg is negative. If you connect these wrong, the LED won't come on, electricity won't flow, and there will be an open circuit.

You can try disconnecting fuse 11 in the front fuse box for 5 minutes and see if the CEL goes away. If it doesn't you may need to disconnect the battery for 5 minutes and when you reconnect see if the CEL goes away. A flashpaq would let you clear the Check Engine Light.



I hooked up the MDS light on my Charger Hemi. I used a 12 vold LED, no switch. When I first started it up, it was missing on at least one cylinder and the light was on at idle. I disconnected it right away. Now the engine light is on all the time!, but it runs fine. I used the brown with blue stripe wire and ground. Can the color code be different on my Hemi? HELP! How do I clear the codes and turn off the light? Why the heck didn't this work?

dewey cheatham
08-30-2006, 12:57 PM
Thanks, Quarky. I think maybe I hit the wrong wire. It was dark and I was tired. I should have checked it out. The LED works fine (polarity right) as it was blinking wildly (maybe injector 8).
BTW, What's a "flashpaq"? I'll try the fuse/battery disconnect tonight.

dewey cheatham
08-31-2006, 02:08 PM
UPDATE: Didn't have time to do anything last night. This morning the engine light is off. I guess it healed itself!!

dewey cheatham
09-05-2006, 11:06 PM
Here's the latest on my MDS indicator project. I put in a 12 Volt LED instead of a switch or light. I mounted it in one of the unused switch positions above the radio. The led worked for about 5 seconds and burned out. The inductive kickback from the MDS valve lifter solenoids killed the LED because LEDs have a very low reverse voltage rating normally. To correct this, and make it brighter, I used a standard LED (usually rated at about 3 volts) with a tiny current limiting resistor (680 Ohms, 1/4 Watt) and a 1N4003 diode to prevent the reverse voltage kick from getting to the LED. The finished product works great.
BTW, I did have the wrong brown/blue stripe wire at first, but all is OK now.
I can go into greater detail if anyone is interested.
4986

(http://users2.ev1.net/%7Esoltysik/pictures/MDS-3.jpg)

joseph
09-11-2006, 01:21 AM
[quote=dewey cheatham;488572]Here's the latest on my MDS indicator project.
I can go into greater detail if anyone is interested.

Please do, post pictures of the wiring showing all the connections in the engine compartment.
I plan on putting my LED near the light switch.

dewey cheatham
09-11-2006, 11:44 AM
I'm sorry I didn't take more pictures when I had it all apart, but I followed the directions in the original post very closely. First thing to do it locate where you want the indicator (LED or light) and take the bottom of the dash apart including the shiny panel. If you don't take that off, you will leave bits of flesh on it when you run the wire! I poked a hole through the grommet just as the instructions said. It was pretty tough, but you need a sharp pointed long object. I used a piece of 1/8" welding rod sharpened on the end. I ran some speaker wires through the hole into the engine compartment using the welding rod to pull them through the grommet. I routed them to the passenger side fender wall to connect to the control module. That's where I originally screwed up. It was dark and I didn't see the two brown/blue striped wires. One of them is the correct one. Of course I picked the wrong one. It caused a miss and set the check engine light. To determine if you have the wrong one, check from the one you want to use to ground with a volt meter with the engine running. If you get voltage, it's the wrong one. I hooked my speaker wire to the right wire using the bullet connector just like the pictures show. I used a module mounting bolt for the ground for the other wire. If you are using a LED, be sure you have the polarity right or it won't light. To test that, unhook the bullet connector you installed and hook a clip lead from your speaker wire on the bullet connector to the battery +. It should light the LED. Be sure to read my post about the LED protection diode. I blew one away in 10 seconds without it.
To get the unused switch cover off I just pried it out from the drivers side with a small screwdriver. I drilled it and then VERY carefully burned a hole in the side of the switch body (toward the driver) with a hot end of a welding rod for the wires to get out. There's a circuit board blocking a rear exit for your wires. I crammed the LED, resistor and diode into the unused switch top and repopped it in place.
Hope this helps Joseph and others.:beerchug: DC

quarky42
09-11-2006, 11:04 PM
I have a 1.7 and 2.1 Volt DC LEDs on hand. I plan on using a 510 or 560 ohm 1/4 watt resistor to protect the LED.

1. Do you think MDS would get pi$sed off if it sees that resistance on that line? Sounds like Dewey used this setup without a problem.

2. Do you have any details on which direction the protection diode is connected and on which leg it is on? (I haven't seen that protection diode... does it have a line on it or something...and which terminal does that line connect to... ?)

ccl088
09-11-2006, 11:53 PM
Anyone know why the Daytona has 10 more HP?What is it that gives it 10 more HP?

dewey cheatham
09-12-2006, 11:53 AM
Quarky, I think either LED will be fine and your resistor should also be OK. The diode protects the LED from the inductive kickback from the valve lifter solenoid coils. I put the resistor on the + side of the LED going to the module, and the diode on the ground side of the LED. The banded end of the diode should be the ground wire, the other end goes to the LED (minus side). Any diode with a reverse voltage greater that 150 volts and a forward current rating of greater than 0.1 amps should be fine.

quarky42
09-12-2006, 05:14 PM
Thanks. Excellent info! Beans for you!

Todd RT
09-12-2006, 05:42 PM
Anyone know why the Daytona has 10 more HP?What is it that gives it 10 more HP?

Not sure what this has to do with teh MDS light... but anyways...

No Intake Eardrum thingy... different exhaust.

IT Rider
10-18-2006, 03:04 PM
I'm going to radioshack later on and want see if I have to go through the trouble of the resistor/diode installation or if the 12v LED works okay.

I wonder if dewey cheatham's issue was because the wrong wire was initially used.

Thoughts?

wayne43
10-22-2006, 10:14 PM
I have a 2006 Jeep Grand Cherokee Overland with a 5.7 Hemi with MDS. I installed indicator light as instructed. Light is on all the time when engine is on. Any ideas as to why? Shouldn't light be off and turn on only when MDS is running on 4 cylinders?
My PCM looks just like yours but maybe my brown and blue wire is not the same as yours. And maybe my pin 28 does not control the no. 4 cylinder.
Any help would be greatly appreciated.

lafrad
10-22-2006, 10:41 PM
are you sure that's not the torque converter locking up?
I too have noticed the RPM changes with MDS.

I don't have a light, but hearing the sound of the exhaust note (I can hear a little little different), it appears that, when MDS is "ON", the RPM's are about 100-200 rpm *higher* than when MDS is "OFF". This is something I noticed when going on level road, then hitting a hill, in cruise control. On the level road... (lets say) the Tach read 2100 rpm. As soon as I got to the hill.. I feel a little, little "bump", and I see the Tach read 2000 rpm, along with the exhaust sounding 'Smoother'.

My guess to this was: In MDS mode, the torque converter is in Mercedes' "Partial Lockup" mode... to even out the 2 power pulses per rev, instead of 4 (and giving the car a rougher feeling)... when it goes to 8 Cyl mode, it can lockup fully, to get the best gas milage it can get...

fnkychkn
10-22-2006, 10:57 PM
I have a 2006 Jeep Grand Cherokee Overland with a 5.7 Hemi with MDS. I installed indicator light as instructed. Light is on all the time when engine is on. Any ideas as to why? Shouldn't light be off and turn on only when MDS is running on 4 cylinders?
My PCM looks just like yours but maybe my brown and blue wire is not the same as yours. And maybe my pin 28 does not control the no. 4 cylinder.
Any help would be greatly appreciated.
although i haven't done this to a GC, i have done it to a DR ram truck and it works fine. pin 28 is definitely the deactivation feed for the #4 MDS solenoid on your GC as well as all 5.7L with MDS.

magnuman
10-22-2006, 11:57 PM
Are you sure you have the Pin 28 wire? If you have the Pin 4 wire, you'll get an almost continuous light. See note below from instructions.

There is more than one brown/light blue striped wire on plug C1 of the PCM.

The brown/light blue wire we are concerned with is the one that goes to Pin 28, the MDS solenoid for the No. 4 cylinder. (The other brown/light blue striped wire goes Pin 4 and is connected to the injector control for the No. 8 cylinder. There is also a plain brown wire with no stripe going to pin 33, which is the No. 2/2 oxygen sensor signal lead.)

Keep us posted on what you find.

IT Rider
10-23-2006, 09:24 AM
Per the approval of DMAG, I updated his MDS "ON" Light Install Guide. Thre is the link:

http://home.comcast.net/~mzuro226//itrider/downloads/MDSLightInstallManual.pdf

DMAG
10-23-2006, 04:43 PM
Added IT Rider's pdf to the first post in this thread.

Good job! :wink:

magnuman
10-23-2006, 08:22 PM
Excellent job, IT!! Thanks for clarifying and the great pix. Much better job than I could ever do, LOL.

wayne43
10-25-2006, 01:17 AM
Are you sure you have the Pin 28 wire? If you have the Pin 4 wire, you'll get an almost continuous light. See note below from instructions.

There is more than one brown/light blue striped wire on plug C1 of the PCM.

The brown/light blue wire we are concerned with is the one that goes to Pin 28, the MDS solenoid for the No. 4 cylinder. (The other brown/light blue striped wire goes Pin 4 and is connected to the injector control for the No. 8 cylinder. There is also a plain brown wire with no stripe going to pin 33, which is the No. 2/2 oxygen sensor signal lead.)

Keep us posted on what you find.

You were right! I had connected to the wrong brown/light blue wire. Here was the problem. Looking at the diagram of the module powertrain control C1,I had assumed that the #28 pin was just above the #29 pin. If I had actually counted the pins I would have seen that the #28 pin was on the opposite side of the module and that the pin above the #29 pin was actually the #20 pin. Also, I didn't know that the cover of the module could be removed so that you could see where each wire connected to the pins. With the cover on, all you could see where the bunched wires came out of the cover after turning 90 degrees. So, looking at the bunched wires, I chose the brown/light blue one on the same side as the #29 pin( I thought the 28 pin was just above it) instead of the wire on the opposite side of the module.
But after looking at the latest update of the "Installation of a MDS ON Indicator Light" , the new pictures made it perfectly clear where the correct wire is located!
I used a 276-084 red LED from Radio Shack. It has a built in 1/4 W, 680-ohm resistor and is rated for 12 volt operation. I mounted it under the hood in the windsheild wiper depression and it can easily be seen and yet it is not distracting. So far it seems to work fine and I will let you know if problems show up later. One last question--the saddle type wire splice used on the wrong wire at the first try---should I leave on or will removing it leave the wire damaged?
Thanks to all of you for your help and advice!

IT Rider
10-25-2006, 09:15 AM
One last question--the saddle type wire splice used on the wrong wire at the first try---should I leave on or will removing it leave the wire damaged?
Thanks to all of you for your help and advice!

That is a very good question. Personally, I would take some time, cut that wire, solder it together and use a shrink tube. If you do not want to do that much effort, I would suggest leaving it on (so not to expose the bare wire that it is cut into) and tape the heck out of it.

Good luck!

joseph
12-12-2006, 03:36 AM
I did mine the easy way, no confusion here:

I did not disconnect the battery, I did not unplug the PCM plug, just remove the cover and you'll see wire # 28, then connect a wire to it, then route it whichever way you like to the grommet to go inside the cabin to be connected to the switch.
http://i60.photobucket.com/albums/h7/pjosephlv/Magnum%20RT/th_100_1382.jpg (http://i60.photobucket.com/albums/h7/pjosephlv/Magnum%20RT/100_1382.jpg)

http://i60.photobucket.com/albums/h7/pjosephlv/Magnum%20RT/th_100_1383.jpg (http://i60.photobucket.com/albums/h7/pjosephlv/Magnum%20RT/100_1383.jpg)

http://i60.photobucket.com/albums/h7/pjosephlv/Magnum%20RT/th_100_1384.jpg (http://i60.photobucket.com/albums/h7/pjosephlv/Magnum%20RT/100_1384.jpg)

http://i60.photobucket.com/albums/h7/pjosephlv/Magnum%20RT/th_100_1385.jpg (http://i60.photobucket.com/albums/h7/pjosephlv/Magnum%20RT/100_1385.jpg)

http://i60.photobucket.com/albums/h7/pjosephlv/Magnum%20RT/th_100_1386.jpg (http://i60.photobucket.com/albums/h7/pjosephlv/Magnum%20RT/100_1386.jpg)

After routing the wire thru the firewall grommet (PITA part), put your switch where you want it, make a wire and connect it to the plate (ground) (see photo)

Right side wire is from wire 28 from PCM, left side is ground.
http://i60.photobucket.com/albums/h7/pjosephlv/Magnum%20RT/th_100_1387.jpg (http://i60.photobucket.com/albums/h7/pjosephlv/Magnum%20RT/100_1387.jpg)

Put everything back, I have a switch from Pepboys, it's an LED switch, I got the green one, they have blue also, I can turn it off if I'm tired of that light flashing, it's great, now I can see when it goes into 4 Cyl mode, which is surprisingly quite often.

http://i60.photobucket.com/albums/h7/pjosephlv/Magnum%20RT/th_100_1388.jpg (http://i60.photobucket.com/albums/h7/pjosephlv/Magnum%20RT/100_1388.jpg)

marwady
12-29-2006, 04:40 PM
Just finished the MDS light mod and, thanks again to the knowledgeble members of this forum, it was a piece of cake.

I found a nice little LED at Radio Shack (part # 276-085) and mounted it on the dash in a place that won't bug me but I can still see well.

http://i79.photobucket.com/albums/j126/marwady/Automotive/P1000131.jpg

I actually pulled the bezel assembly so I could mount it and it was fairly easy. After you remove the lower cover, you will see 5 phillips screws along the bottom edge of the assembly. Remove those and gently pull from the bottom and sides, it will just pop out. BTW, it looks like that's the way the instrument cluster is removed if you have to.

I drilled a 3/16" hole and filed it for the final snug fit. Re-assembled, tied everything off and went for a test drive. After the car warmed up, MDS started doing its thing....very cool.

THX again to all the members who made this a nice and easy (and cheap) mod.

Cheers!!!

joseph
02-06-2007, 03:19 AM
I just replaced that crappy looking LED switch with one that fits flush ($2 from Autozone), looks a thousand times better.

Before
http://i60.photobucket.com/albums/h7/pjosephlv/Magnum%20RT/th_100_1388.jpg (http://i60.photobucket.com/albums/h7/pjosephlv/Magnum%20RT/100_1388.jpg)

After
http://i60.photobucket.com/albums/h7/pjosephlv/Magnum%20RT/th_100_1634.jpg (http://i60.photobucket.com/albums/h7/pjosephlv/Magnum%20RT/100_1634.jpg)

http://i60.photobucket.com/albums/h7/pjosephlv/Magnum%20RT/th_100_1635.jpg (http://i60.photobucket.com/albums/h7/pjosephlv/Magnum%20RT/100_1635.jpg)

http://i60.photobucket.com/albums/h7/pjosephlv/Magnum%20RT/th_100_1636.jpg (http://i60.photobucket.com/albums/h7/pjosephlv/Magnum%20RT/100_1636.jpg)

Sodes
02-10-2007, 10:19 AM
I just installed my MDS light last night. I was a little confused about the ground wire as well, joseph, but your post and the write up together helped work it out, thanks.

Marwady, I liked your installation so much I did the same thing. Slightly different location though. I also installed a hinden switch under the dash so I can turn the light off if it gets annoying at night.

I'll post a picture as soon as the baby stops crying.

Sodes
02-13-2007, 01:42 PM
Baby stopped crying... here's my location

done
05-09-2007, 03:43 PM
There is another wire that carries the MDS signal for this mod that is easier to get to.

Go to the factory wiring harness plug that is just beside the evaporator purge valve at he edge of the firewall. You will see a large rectangular connector attached to the bottom of the strut tower support brace.


8418

Pull down firmly on the harness connector. It will make a little noise as the Christmas tree clip comes out of the strut tower support brace. Pull the corrugated wire tubing back a little bit and look for a brown wire with an orange stripe. You may have to take your utility knife and very gently cut back the black electrical tape covering the wires. Using a dull flat instrument, separate the wire away from the other so that you can use a ‘scotch-lok’ or ‘vampire’ tap to connect the MDS indicator wire to the brown wire with an orange stripe. Wrap around the connection firmly with some electrical tape and then tuck everything back into the corrugated wire tubing as best as you are able. Then find the hole that the Christmas tree clip came out of and reinstall the harness connector to its original position on the strut tower support brace.

joseph
05-09-2007, 06:14 PM
There is another wire that carries the MDS signal for this mod that is easier to get to.

Go to the factory wiring harness plug that is just beside the evaporator purge valve at he edge of the firewall. You will see a large rectangular connector attached to the bottom of the strut tower support brace.


8418

Pull down firmly on the harness connector. It will make a little noise as the Christmas tree clip comes out of the strut tower support brace. Pull the corrugated wire tubing back a little bit and look for a brown wire with a light blue stripe. You may have to take your utility knife and very gently cut back the black electrical tape covering the wires. Using a dull flat instrument, separate the wire away from the other so that you can use a ‘scotch-lok’ or ‘vampire’ tap to connect the MDS indicator wire to the brown wire with an orange stripe. Wrap around the connection firmly with some electrical tape and then tuck everything back into the corrugated wire tubing as best as you are able. Then find the hole that the Christmas tree clip came out of and reinstall the harness connector to its original position on the strut tower support brace.

Good find:thumbs_u: , how did you find out about this wire?

LX HEMI
08-17-2007, 03:40 AM
There is another wire that carries the MDS signal for this mod that is easier to get to.

Go to the factory wiring harness plug that is just beside the evaporator purge valve at he edge of the firewall. You will see a large rectangular connector attached to the bottom of the strut tower support brace.


8418

Pull down firmly on the harness connector. It will make a little noise as the Christmas tree clip comes out of the strut tower support brace. Pull the corrugated wire tubing back a little bit and look for a brown wire with a light blue stripe. You may have to take your utility knife and very gently cut back the black electrical tape covering the wires. Using a dull flat instrument, separate the wire away from the other so that you can use a ‘scotch-lok’ or ‘vampire’ tap to connect the MDS indicator wire to the brown wire with an orange stripe. Wrap around the connection firmly with some electrical tape and then tuck everything back into the corrugated wire tubing as best as you are able. Then find the hole that the Christmas tree clip came out of and reinstall the harness connector to its original position on the strut tower support brace. So you're just tapping into the brown/LBS with with the green wire? And the green one is lead to the LED light? That's it?

done
08-17-2007, 11:23 AM
So you're just tapping into the brown/LBS with with the green wire? And the green one is lead to the LED light? That's it?


Yes, just run a wire from the tap to your LED and ground the other side of the LED and you are done.

ravenkeeper98
08-17-2007, 11:51 AM
There is another wire that carries the MDS signal for this mod that is easier to get to.

Go to the factory wiring harness plug that is just beside the evaporator purge valve at he edge of the firewall. You will see a large rectangular connector attached to the bottom of the strut tower support brace.


8418

Pull down firmly on the harness connector. It will make a little noise as the Christmas tree clip comes out of the strut tower support brace. Pull the corrugated wire tubing back a little bit and look for a brown wire with a light blue stripe. You may have to take your utility knife and very gently cut back the black electrical tape covering the wires. Using a dull flat instrument, separate the wire away from the other so that you can use a ‘scotch-lok’ or ‘vampire’ tap to connect the MDS indicator wire to the brown wire with an orange stripe. Wrap around the connection firmly with some electrical tape and then tuck everything back into the corrugated wire tubing as best as you are able. Then find the hole that the Christmas tree clip came out of and reinstall the harness connector to its original position on the strut tower support brace.

Just curious, which wire is it? You mentioned 2 different wires a brown with light blue stripe and a brown with orange stripe

LX HEMI
08-17-2007, 12:05 PM
oh, nice catch...so which one, which one, which one?

done
08-17-2007, 03:01 PM
Just curious, which wire is it? You mentioned 2 different wires a brown with light blue stripe and a brown with orange stripe

Hmm, a typo. Original post corrected. It is the brown wire with the orange strip.

Go Browns
11-13-2007, 01:44 AM
Has anyone tried this new simple way of installing an mds indicator light? I would like to try it next week, but am not good enough w/ electrical stuff to know if i did it right so i am looking for feedback from people who have completed it successfully. Any tips would also be greatly appreciated, such as what kind of wire to use from brown wire to led bulb. Thanks

SouthernComfort
11-14-2007, 04:11 PM
Thanks for this mod

oldschool
11-14-2007, 04:46 PM
I prefer a dashhawk...

Good mod though

craigreilly
12-08-2007, 08:54 PM
this is great... might try it out...

2005 Jeep GC
5.8l HEMI MDS v8 Engine

blacksleeper
12-26-2007, 07:15 PM
Thanks DMAG for the detailed write-up.:thumbs_u: I just finished doing my MDS light. I opted for a more simple setup without a switch. I used a very small green LED (12v), and installed it between the speedo and tach on the lower side of the two. Drilled a hole in the gauge trim, pushed the LED in from behind, and slapped a whole bunch of GOOP to hold it and the wires in place. The biggest pain was feeding the wires through the firewall grommet just above the hood release cable grommet.
The total cost for this mod was $1.29 for a package of 3 LEDs from Sayal Electronics in Cambridge, I had speaker wire already.
Thanks again. Works like a charm:hammer:, just wish it would come on more often...

southercomforthemi
02-24-2008, 11:35 PM
if we can have a light when mds is on....can we have a simple switch to turn MDS off without any codes??????????

done
02-26-2008, 12:08 PM
if we can have a light when mds is on....can we have a simple switch to turn MDS off without any codes??????????

No, but if you just want to waste gas, the Diablo tuner has an MDS off setting.

Scarbs
03-05-2008, 12:59 AM
I did the Done MDS mod version, works 100%. I added an Led to the light switch panel.

I took the car out for a ride,Around town the mds comes and goes but on the highway like clock work a few seconds after cruise kicks in the light comes on. This will help on trips and around town. Its like a game try and get the light to stay on for the longest time.

Thanks guys

E

Now with a pic!

http://i30.photobucket.com/albums/c323/scarbrs/100_0322.jpg

magn3t0
08-27-2008, 08:37 PM
Hi I just purchased a 2005 magnum rt and it has 2 led lights and a toggle and a push toggle. I guess the last owner attemped to do this mod. But it looks like he spliced into the wire off of the coil back nearest to the driver side. Im unsure of which cyclinder this but im just confused how he wired it up and, I cant make it work I can rewire It but I dont know what all hes got done..? I can get pics if need thanks for any input!

done
08-27-2008, 10:07 PM
Hi I just purchased a 2005 magnum rt and it has 2 led lights and a toggle and a push toggle. I guess the last owner attemped to do this mod. But it looks like he spliced into the wire off of the coil back nearest to the driver side. Im unsure of which cyclinder this but im just confused how he wired it up and, I cant make it work I can rewire It but I dont know what all hes got done..? I can get pics if need thanks for any input!


See post #86 to locate a convenient place to tap into the MDS control voltage. It will be +12VDC when MDS in engaged. Wire the plus side of the LED to that location and then ground the other side of the LED. If you wish, you can run the connection through a switch. I did, but I leave mine on all the time anyway.

turfinator
08-30-2008, 10:25 PM
Lots of great info here. Ive got an 08 Ram that I'd like to do this mod to and was wondering if anyone else has done it yet on a ram. The PCM runs vetical on the firewall and I'm not sure which plug is the C1 plug. Would everything else be the same once I have identified the correct plug? Would doing this have any warranty implications?

bigkevin20
08-31-2008, 10:04 PM
This was a great post in all of my years hear this mod is by far one of the best. I installed my light inside the center left air vent only I can see it and if I dont want to just close the vent. IMO its the best location.

4life
09-02-2008, 09:18 PM
Looks like the 2009 cars will be coming with this light already installed in the dash.

bigkevin20
09-03-2008, 10:59 AM
I think they have it now it just says fuel saver mode.

MikeEast
09-03-2008, 02:25 PM
When I ran the wire from under the hood to the cabin for the led for the Labonte w/m system, I ran a chunk of plenum grade cat5. Now I have a bunch of signal grade wires to use for stuff like this.

Now to find another little green led...

Mike

HemiHearse
10-18-2008, 05:57 PM
Did mine today like "done" posted on 5/9/07. Ran the wire through the rear cowl brace, a muther to fish through, yet makes for a clean invisible install. Mounted a neon 1/2" light below the key switch.
http://i299.photobucket.com/albums/mm291/HemiHearse/MDSLight.jpg
The bracket I made from a piece of plumbers strap.
Just enlarged the hole to 1/2", bent it over and rounded it up some for looks.
3 hours and $3, and yeah, it works great.
Better late than never I guess.. since this was posted April 05!

carbonater55
04-07-2009, 06:57 PM
Just completed the mod.

One suggestion. The hood release cable boot. Lower left of the steering column from inside the car, is much easier to access and run a wire thru. Take off the Master cyl. inspection cover and shine a lite down the firewall

bigkevin20
04-08-2009, 09:49 AM
I still think the best location out of all of them is deep inside your AC duct vent. I have mine on the left side above the radio its completely hidden and you will always see it in the corner of your eye. I have it mounted back in the vent you cant see it when its off. IMO

philnhemi
12-17-2009, 06:19 AM
2006300c
what vehicle functions will i have to reset if i disconnect the battery and how do i do them?

SoCal Gixxer
12-17-2009, 09:36 PM
hmm my 08 "C" does this with the EVIC, in the corner of it, when MDS is on, it just say mds diagonally

Montreal300
12-18-2009, 10:47 AM
Here's my installation.20974

Tomguy
12-31-2009, 11:26 AM
I did this mod Christmas Day AM before leaving on a trip to Ithaca. It is odd to see how MDS functions, and how I thought I was saving gas when I really wasn't. Sometimes when coasting MDS doesn't go on, but when I give it a teensy bit of throttle it turns on. I'm going to have to update my driving style!

I really only used the directions for which pin & how to go thru the firewall grommet, since I'm pretty electronically inclined. I got a RadioShack orange LED in the holder & now I am debating where to mount it. I'm thinking inside my center console cubbyhole, or maybe behind that empty "button" in the center above the radio.

The part I did differently is that rather than tapping into a speaker or another source for ground, I just used the metal plate. I put the wire between the metal plate & the support and tightened the nut. Remember, any part of a car's chassis is (-) ground and this is just an LED, so it doesn't need precisely 13.8V to function right :)

charger_john
01-13-2010, 05:39 PM
Looks like the 2009 cars will be coming with this light already installed in the dash.

That's news to me, my 2009 Charget RT does not have an indicator light.

Magnesium0210
01-19-2010, 11:21 PM
Okay does anyone have a link to the photos that work? I saw the one the the member had posted that was a different type of installation, but I would like to see the original version that had been posted from the #6 solenoid. If anyone has the photos I would be appreciated.

sasha1414
04-01-2011, 01:30 AM
Okay does anyone have a link to the photos that work? I saw the one the the member had posted that was a different type of installation, but I would like to see the original version that had been posted from the #6 solenoid. If anyone has the photos I would be appreciated.

Just follow the pdf (http://lxforums.com/articles/MDS_light.pdf) on the 1st page it's an awesome write up and I just did it today and it works (06 magnum).

Thought I'd mention I put a 1Kohm resistor (for protection) in the line, w/o a diode (couldn't fine one, if LED dies then I'll look into it) also I used a 24 gauge single prong wire to do this. It was much harder to work with but telephone wire was all I had. Instead of a switch I used a ~3V LED. Also I found it easier to lead only one wire through the firewall and ground the LED under the dash

Bahndrvr
12-30-2011, 07:37 PM
Did the mod to my woman's Hemi because we were getting horrible mileage, confirmed mDS wasn't working then threw the replacement part in and am now loving keeping that light on as long as possible:)

carbonater55
12-30-2011, 11:08 PM
What part did you replace???

Bahndrvr
12-31-2011, 12:12 AM
Ended up being the oil pressure sensor, 30 bucks and about thirty minutes of work and now MDS works, put the light in to confirm it wasn't working then started searching:). Had a bunch of codes but 2 pointed to it, replaced it and bam, at 250miles on the tank at half a tank right now, that's what we were getting on a full tank before, hoping for mid 20's previous best was 22 before the CAI and tune.

Montreal300
12-31-2011, 11:11 AM
I did this mod Christmas Day AM before leaving on a trip to Ithaca. It is odd to see how MDS functions, and how I thought I was saving gas when I really wasn't. Sometimes when coasting MDS doesn't go on, but when I give it a teensy bit of throttle it turns on. I'm going to have to update my driving style!

I really only used the directions for which pin & how to go thru the firewall grommet, since I'm pretty electronically inclined. I got a RadioShack orange LED in the holder & now I am debating where to mount it. I'm thinking inside my center console cubbyhole, or maybe behind that empty "button" in the center above the radio.

The part I did differently is that rather than tapping into a speaker or another source for ground, I just used the metal plate. I put the wire between the metal plate & the support and tightened the nut. Remember, any part of a car's chassis is (-) ground and this is just an LED, so it doesn't need precisely 13.8V to function right :)

Quick note to those of you with the 2006 models. When I first got my predator, it said I needed an OEM update to the PCM. Once updated, I noticed a big difference in the way MDS reacted. It came in sooner and stayed on for much longer periods of time. This is without loading any of the Predator tunes. So even if you don't have a predator, check with your dealer to see if the update applies to your car.

jross239
11-06-2013, 08:07 PM
I know that this is a very old thread.

I'm only getting 13.2-13.7 mpg combined driving, so i was looking up on Google if there was a way to install an MDS light to see if it was working or not, and it led me to this forum.

I read all they way through the simple install and saw comment #120 by Bahndvr. I have to fill up every 250 miles or so. I'm wondering if there are any notifications of the oil pressure sensor being bad or not. Can you do the key toggle and get this code? Or do i have to use an OBD II reader to get the code? I dont have a CEL on and the car seems to run ok other than the $hitty gas mileage.

I will probably be doing this mod over the weekend, but if i can see about any codes and see if that sensor on my 06 AWD R/T with 115k is bad prior would be awesome.

jross239
11-09-2013, 10:05 PM
So I installed a MDS light today to see if my oil pressure sensor was faulty or not and to see if my MDS was even turning on.

When i opened up the PCM I found that somebody had already been in there
http://i50.photobucket.com/albums/f346/jross13450/IMAG0367_zps09cc4970.jpg (http://s50.photobucket.com/user/jross13450/media/IMAG0367_zps09cc4970.jpg.html)

http://i50.photobucket.com/albums/f346/jross13450/IMAG0368_zps3e82283f.jpg (http://s50.photobucket.com/user/jross13450/media/IMAG0368_zps3e82283f.jpg.html)

I cut out the crappy solder job and installed the lights

http://i50.photobucket.com/albums/f346/jross13450/IMAG0373_zps8b834e26.jpg (http://s50.photobucket.com/user/jross13450/media/IMAG0373_zps8b834e26.jpg.html)

MDS is working

ravenecw
06-26-2014, 09:34 PM
I want to do this on my 2007 Jeep Grand Cherokee but am a little nervous... is there anyone that is willing to help me do this? Please let me know, thank you.

Montreal300
07-01-2014, 04:31 PM
I want to do this on my 2007 Jeep Grand Cherokee but am a little nervous... is there anyone that is willing to help me do this? Please let me know, thank you.

It might help if you identify where you are.

ravenecw
07-01-2014, 04:48 PM
It might help if you identify where you are.

I'm on the Michigan/Wisconsin border... if someone was willing to help out in person that would be great too but i'm just a little nervous doing something with the wrong wire etc. I see the instructions but not as many pictures (or video) plus it seems the pictures are from an '05 if i'm not mistaken. Just want to be sure of what i'm doing (or if someone is close enough that would be great too! I can supply beer or work out a deal lol).

Montreal300
07-01-2014, 05:31 PM
Use the method in post 86, it's way easier. 2006 and 2007 wire color codes are the same and the connectors are in the same place. You're too far away for me to help but maybe someone else can.

ravenecw
07-01-2014, 06:09 PM
Use the method in post 86, it's way easier. 2006 and 2007 wire color codes are the same and the connectors are in the same place. You're too far away for me to help but maybe someone else can.

I don't see anything that looks like that picture.. I do see a spot that could be it though. I'm trying.... just not "doing" anything until I know for sure.

ravenecw
07-02-2014, 05:38 PM
I am trying to upload pictures of what i'm looking at and hoping to get help with it but I can't pictures to upload

ravenecw
07-02-2014, 06:12 PM
54726


Is this the correct wiring? If so, what side do I "tap" into?

Pale Rider
07-02-2014, 06:41 PM
Is this the correct wiring? If so, what side do I "tap" into?

I'm not trying to be a jerk, really, I'm trying to be helpful here, but, isn't there a forum out there for the Jeeps? I just don't know how you could feel confident that our LX wiring would be the same as your wiring. I'd think it'd be a completely different harness. Maybe different colors.

ravenecw
07-02-2014, 09:30 PM
I'm not trying to be a jerk, really, I'm trying to be helpful here, but, isn't there a forum out there for the Jeeps? I just don't know how you could feel confident that our LX wiring would be the same as your wiring. I'd think it'd be a completely different harness. Maybe different colors.

I got here through a jeep forum because they copied what was done on this thread but I wanted to be sure since I wasn't as confident without clearer pictures and "hopefully" help from some other people that did this mod.
I will go back to the jeep forum though and try to get more help there, sorry to be bother.

Cazca
12-21-2014, 06:02 PM
Will this work for a 2011 Charger?

Montreal300
12-23-2014, 11:20 AM
The Charger has "ECO Mode" shown on the EVIC but as you probably know this doesn't mean that MDS is on. If ECO is indicated it means you have reached a driving method that saves fuel but it doesn't mean that MDS is on. By extension, if MDS is on then the ECO light will be on.

Cazca
12-23-2014, 06:01 PM
The ECO mode seems to come on anytime you're within a specific RPM range for whatever gear your in. Seems to work completely independent from the MDS.

I guess I'll have to give this a try to see if it works for the 2nd gens.