[JOHNTOYTECH]

How do you know if the mds is working i just took my first long roadtrip 17.8 mpg at 70mph on cruise, i get 13.1 around town and i do not hear any noticeable noise like it kicking down to to 4cyl i am a driveability tech for toyota so i know cars but do not understand this system enough to know if it is working any comments would be helpful.. i also heard this system might have to be reset. only own the car two months runs great i use 89 octane and have not beat on it my trailblazer ss wich was heavy modded used to get 12 city 16 highway i thought this would be better. i love the car but thought economy would be better:banghead:

 

[Magnum Power]

After some carefull listening, you will hear a sound differance. A lower tone change to the engine noise. It is very slite and hard to hear. I don't ever remember hearing about a reset for MDS. I'm sure others will be chimming in.

 

[gameover]

Numbers look pretty low. How long was the road trip? Might have to pull fuse 11 to reset the adaptives.

 

[Magnum Power]

Now that reset is right, pull the fuse in the #11 slot, in the fuse box under the hood.

 

[TheMoparKid]

Check the o2 sensors. A faulty o2 sensor will not allow MDS to kick on.

However, some cars just get horrible mileage. My Friends 06 R/T has never bested 18mpg ever.....highway or city.

 

[fnkychkn]

make sure you use 5W20 motor oil. MDS doesn't work very well with other grades.

you can install yourself an indicator lamp for the MDS. http://www.lxforums.com/board/showthread.php?t=11575

 

[Gucci300C]

all of the above and more important if your using autostick that doesnt allow the mds to kick on. also make sure that nothing 5-20 is going into your motor as fnky stated the mds doesnt like to use any other oil besides that

 

[FloridaRT]

Your gas mileage is really low, how many miles on it? Spark plugs should be changed every 30,000 miles. I get 17-19 around town and 24-25 on highway at 70 MPH. I did get 31 MPG at a steady 55MPH, no A/C and using cruise control.

Bob

 

[JOHNTOYTECH]

thanks for all the quick replies

it has 22,000 miles on it do not use the autostick other that around town and the dodge dealer changed the oil before i bought it. i will try the fuse pull and post what happens the drive was 4 hours each way2 people in the car 1 suitcase and nitrofill in all 4 dunlop preformance sp tires no up grades yet looking to mod soon but want to do it right but this was just bugging me.:blam: Also i see everyone saying 5w20 i have like 3 cases of mobil 1 5w30 from my tbss this i take it will not work in these cars.:doh:

 

[CanuckDWfan]

Yeah, 5W30 won't allow the MDS to kick into 4 cyl mode as often. MDS is very sensitive to the oil viscosity.

As far as the MDS reset procedure, this is copied from the Battery Disconnect thread in the Knowledge Base:

08-13-2005, 07:45 AM
frank29

LX Newbie
iTrader: (0)
Join Date: Jul 2005

I think M.D.S. reset is required in some cases. I have previously disconnected the battery with no M.D.S. ramifications; however, after a recent disconnect, my M.D.S. was inoperative. It seems to be a hit or miss thing. I am not positive the problem was related to the battery disconnect; I am positive M.D.S. wasn't working.

I hardly ever reset my average milage display. Normally, it hovers around 18. Recently, it dropped to 14. No change in driving habits. I reset my MPG reading and only got 17 mpg over a 30 mile trip using cruise control set at 60 miles per hour (it should have been 24 or so). I followed the MDS reset procedure and, PRESTO, my average m.p.g. jumped up to its historical levels.

My 05 300C owner's manual & service manual make no mention of this; however, the 06 owner's manual does. The second edition of the 05 Grand Cherokee does mention it. It seems strange M.D.S. reset would be required on some of these extremely similar powertrains and not on others.

If your mileage recently dropped with no change in driving habits, try the following procedure. No flaming required, I am not saying I bought this car with mileage in mind.....I am saying that when there is a drastic drop in mileage that a very simple reset solves, people need to be informed (especially since no documentation from Chrysler refers to the reset, at least for the 05 C models).

Procedure (as copied from another forum):

1. You need a fairly long, open, safe, straight road for a WOT run to about 35 mph.
2. Get engine up to operating temp., engine running and car stopped put selector in "D", move it to the right until in "1".
3. Turn off all electrical accessories (except lights if needed).
4. WOT run to 4500 RPM (about 35 mph), immediately remove foot from accelerator and do not depress the brake, let the vehicle coast with the throttle closed until the vehicle speed is again at 35 mph or lower.
5. Stop vehicle and place in "Park", verify all instrument cluster warning indicators are off.
6. Cycle ignition switch "Off" and back "On", but do not immediately start engine.
7. Hook up StarScan and clear DTC's
8. MDS calibration is now complete.

See entire thread here: http://www.lxforums.com/board/showthread.php?t=11313