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Transmission Control Module (TCM) Location and Access *

199K views 33 replies 23 participants last post by  Thoward 
#1 · (Edited)
The TCM for our LXs is located under and to the left of the steering wheel. It is located just to the right of the Boston Acoustics Amp (if so equipped).

1) To access the module, start by removing the trim piece in the door jam. This piece is held in by two pressure clips and should just pull right out.



2) Removal of this trim piece reveals the first of two screws that must come out. These are both standard #2 phillips screws.



3) The second of two screws is located just to the right of the hood release lever.



4) Now the panel is ready to be removed. It is held in by four pressure clips. Simply pulling on this trim piece should release the clips, and the whole thing should pull away. NOTE: The parking break release will still be attached, so pull away carefully and not too far.



5) The TCM is now visible (circled in red). It is connected via two harnesses (in green) that you must unclip and pull toward the seat.



6) If you're upgrading with a second TCM, by far the easiest thing to do is just slide that new TCM in, just to the right of the original TCM. Connect the wires and the fit should be just right to leave it there and button up.

If you need to replace your TCM, I've heard its a real PITA as the mounting screws are located in areas not easily reached. I haven't done this so I can't help here. Anyone who has please feel free to update here.
 
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#2 ·
EXCELLENT post and pics CV...and 100% accurate.

BTW...you should get a call about your injectors.
 
#6 · (Edited)
Tech's TCM Adaptation Checklist - NAG1 Only

Outstanding post, CV. :thumbs_u: And your timing is exquisite. :wink:

While killing brain cells last night rummaging through the LX Service Manual looking for the poor man's version of what you just did here (to no avail, I might add), I did run across this very helpful Tech's TCM Adaptation Checklist, which essentially gives our new TCM a running start in adapting to its new life in our vehicle. Do this immediately after installing any new TCM.

Just as is the case in the many similar adaptation checklists, the starscan is useful, but not mandatory. Without it you lose the shortcuts. Example: after completion of the adaptation procedure it's necessary to keep the vehicle running for at least 10 minutes to ensure that the adaptives are properly stored. With the starscan one can manually store the adaptives in a few seconds.

OK, without further ado, here's the LX TCM Adaptation Checklist (from page BE - 272, 2005 LX Service Manual), highlighting mine:

TCM ADAPTATION - NAG1 Only

The adaptation procedure requires the use of the appropriate scan tool. This program allows the electronic transmission system to re-calibrate itself. This will provide the proper baseline transmission operation. The adaptation procedure should be performed if any of the following procedures are performed:

• Transmission Assembly Replacement
• Transmission Control Module Replacement
• Clutch Plate and/or Seal Replacement
• Electrohydraulic Unit Replacement or Recondition

1. With the scan tool, reset the Transmission adaptives. Resetting the adaptives will set the adaptives to factory settings.
Note: Perform the Coast Down Adaptations first. The Transmission Temperature must be greater than 60°C (140°F) and less than 70°C (158°F). (Thank you AutoMeter!) Failure to stay within these temperature ranges will void the procedure.
2. Drive the vehicle until the transmission temperature is in the specified range.
3. Perform 4 to 5 coast downs from 5th to 4th gear and then 4th to 3rd gear.
Note: For Upshift adaptation, the Transmission temperature must be greater than 60°C (140°F) and less than 100°C (212°F). Failure to stay within these temperature ranges will void this procedure.
4. From a stop, moderately accelerate the vehicle and obtain all forward gear ranges while keeping the Engine RPM below 1800 RPM. Repeat this procedure 4 to 5 times.
5. Obtaining 5th gear may be difficult at 1800 RPM. Allow the transmission to shift into 5th gear at a higher RPM then lower the RPM to 1800 and perform manual shifts between 4th and 5th gears using the shift lever.
6. The TCM will store the adaptives every 10 minutes. After completion of the adaptation procedure make sure vehicle stays running for at least 10 minutes.
7. It is possible to manually store the adaptives under the 10 minute time frame using the scan tool Store Adaptives procedure.

Note: Validation just in from our favorite fine-feathered Dodge tech: "...definitely worth doing to a new TCM."

So there you have it folks. Don't get caught without this checklist. Print it out now and stash a copy inside your owner's manual. You *will* eventually succumb to the burning need to have one of these wonder boxes in your own ride - it's only a matter of time... :wink:
 
#8 ·
Outstanding post, CV. :thumbs_u: And your timing is exquisite. :wink:

While killing brain cells last night rummaging through the LX Service Manual looking for the poor man's version of what you just did here (to no avail, I might add), I did run across this very helpful Tech's TCM Adaptation Checklist, which essentially gives our new TCM a running start in adapting to its new life in our vehicle. Do this immediately after installing any new TCM.

Just as is the case in the many similar adaptation checklists, the starscan is useful, but not mandatory. Without it you lose the shortcuts. Example: after completion of the adaptation procedure it's necessary to keep the vehicle running for at least 10 minutes to ensure that the adaptives are properly stored. With the starscan one can manually store the adaptives in a few seconds.

OK, without further ado, here's the LX TCM Adaptation Checklist (from page BE - 272, 2005 LX Service Manual), highlighting mine:

TCM ADAPTATION - NAG1 Only

The adaptation procedure requires the use of the appropriate scan tool. This program allows the electronic transmission system to re-calibrate itself. This will provide the proper baseline transmission operation. The adaptation procedure should be performed if any of the following procedures are performed:

• Transmission Assembly Replacement
Transmission Control Module Replacement
• Clutch Plate and/or Seal Replacement
• Electrohydraulic Unit Replacement or Recondition

1. With the scan tool, reset the Transmission adaptives. Resetting the adaptives will set the adaptives to factory settings.
Note: Perform the Coast Down Adaptations first. The Transmission Temperature must be greater than 60°C (140°F) and less than 70°C (158°F). (Thank you AutoMeter!) Failure to stay within these temperature ranges will void the procedure.
2. Drive the vehicle until the transmission temperature is in the specified range.
3. Perform 4 to 5 coast downs from 5th to 4th gear and then 4th to 3rd gear.
Note: For Upshift adaptation, the Transmission temperature must be greater than 60°C (140°F) and less than 100°C (212°F). Failure to stay within these temperature ranges will void this procedure.
4. From a stop, moderately accelerate the vehicle and obtain all forward gear ranges while keeping the Engine RPM below 1800 RPM. Repeat this procedure 4 to 5 times.
5. Obtaining 5th gear may be difficult at 1800 RPM. Allow the transmission to shift into 5th gear at a higher RPM then lower the RPM to 1800 and perform manual shifts between 4th and 5th gears using the shift lever.
6. The TCM will store the adaptives every 10 minutes. After completion of the adaptation procedure make sure vehicle stays running for at least 10 minutes.
7. It is possible to manually store the adaptives under the 10 minute time frame using the scan tool Store Adaptives procedure.

Note: Validation just in from our favorite fine-feathered Dodge tech: "...definitely worth doing to a new TCM."

So there you have it folks. Don't get caught without this checklist. Print it out now and stash a copy inside your owner's manual. You *will* eventually succumb to the burning need to have one of these wonder boxes in your own ride - it's only a matter of time... :wink:
If it was installed at the dealer do you think they would have manually stored the addaptives with the starscan tool ?
 
#12 ·
Will the second TCM stay in next to the original be secure enough just sitting in there ?



6) If you're upgrading with a second TCM, by far the easiest thing to do is just slide that new TCM in, just to the right of the original TCM. Connect the wires and the fit should be just right to leave it there and button up.

If you need to replace your TCM, I've heard its a real PITA as the mounting screws are located in areas not easily reached. I haven't done this so I can't help here. Anyone who has please feel free to update here.[/quote]
 
#13 ·
Has been for me. And I know of at least 3 other installs that have done as I have done; all have had similar success.

Having said that, if it concerns ya, use some doube sided foam sticky tape between the two TCMs. It for sure aint goin anywhere then.
 
#14 ·
Tcm

You *will* eventually succumb to the burning need to have one of these wonder boxes in your own ride - it's only a matter of time... :wink:

This heading starts off with replacing the TCM. I must have missed a previous heading as to why a replacement is necessary. Is the new PCM an upgraded unit that solves some of our shifting problems? TIA
 
#19 ·
You *will* eventually succumb to the burning need to have one of these wonder boxes in your own ride - it's only a matter of time... :wink:

This heading starts off with replacing the TCM. I must have missed a previous heading as to why a replacement is necessary. Is the new PCM an upgraded unit that solves some of our shifting problems? TIA
Meister: What's the scoop ?

TIA
 
#16 ·
Good info guys
 
#17 ·
Hey Cool,
Thank you for the incredible writeup.

You said that - 6) If you're upgrading with a second TCM, by far the easiest thing to do is just slide that new TCM in, just to the right of the original TCM. Connect the wires and the fit should be just right to leave it there and button up.

Am I to understand that you can actually leave your stock TCM in there and slide the custom one alongside it?

Also, do you know if the location of the TCM and the procedures to access it are similar for a 300C?

Thanks,
Tim
 
#21 · (Edited)
#22 ·
The second, aftermarket, TCMs one sees advertised bring promise of raised shift points and better performance while keeping the stock TCM in reserve for visits to the dealer for flashes, etc.

HHP & Heat are/were selling them. Mopar Performance offers one, but only in conjunction with a new ECM, and possibly cam/heads.

Fast56K can raise the shift points on your own TCM to approx 6400 rpm for those desiring shift points higher than the superchips tuner will raise them to.

As with the B&G flash to the ECM/PCM, if one overnights the TCM it will be overnighted back to you, thus your car can be down as little as 24-hours or so in a best-case scenario.

PM him for more info if interested.
 
#25 ·
How do you reset a tcm back to stock after a dealer messes it up? They wont reset it because the only computer guy they had is gone and they are stating that it cannot be undone and are not sure what to do! I have a SC but haven't used it since the new torque was put in and they jacked me up.
 
#26 ·
TCM to stock?

Rush,
Not sure what you're asking.

Did you install a MTCM and have it wank out?
I've not heard of a stock TCM having ant problem, unless it just went bad.

The above thread is talking about installing a performance MTCM, and plugging it in and training it. You can then switch the plugs back to the stock TCM at any time, and you'll get stock TC performance.
 
#28 ·
subscribing for when i need to change it. :beerchug:
 
#29 ·
Just did my install following the directions on this thread.. Thanks guys!! cause of you all i knew what to expect and wat to do... x2 on a smaller torx screwdriver but good luck finding one. i looked at home depot for like 20 min before settling for the bit attachment for a current screwdriver and it wasnt easy getting into that tight area with my king kong hands.... anywho. please follow the directions on this thread and you'll be fine...
 
#30 ·
i had 06 charger with navi 1 rebuilt

Now i got headache its been at amco for 6 months and back forth from dealer to amco and when tranny gets warm goes into limp mode they say they have no idea why so just sits at shop they say we did everything but its crazy it drivee fine as soon as warm up tranny straight limp mode help:panic:
 
#31 ·
Now i got headache its been at amco for 6 months and back forth from dealer to amco and when tranny gets warm goes into limp mode they say they have no idea why so just sits at shop they say we did everything but its crazy it drivee fine as soon as warm up tranny straight limp mode help:panic:
I've seen one case that was rare with a nag1. The case itself had a hairline fracture that allowed fluid pressure to bleed out and cause a limp in mode. The trans was rebuilt a few times before a new unit was installed and problem corrected. Upon disassembly fracture was found in the actual trans case.
 
#32 ·
The TCM for our LXs is located under and to the left of the steering wheel. It is located just to the right of the Boston Acoustics Amp (if so equipped).

1) To access the module, start by removing the trim piece in the door jam. This piece is held in by two pressure clips and should just pull right out.



2) Removal of this trim piece reveals the first of two screws that must come out. These are both standard #2 phillips screws.



3) The second of two screws is located just to the right of the hood release lever.



4) Now the panel is ready to be removed. It is held in by four pressure clips. Simply pulling on this trim piece should release the clips, and the whole thing should pull away. NOTE: The parking break release will still be attached, so pull away carefully and not too far.



5) The TCM is now visible (circled in red). It is connected via two harnesses (in green) that you must unclip and pull toward the seat.



6) If you're upgrading with a second TCM, by far the easiest thing to do is just slide that new TCM in, just to the right of the original TCM. Connect the wires and the fit should be just right to leave it there and button up.

If you need to replace your TCM, I've heard its a real PITA as the mounting screws are located in areas not easily reached. I haven't done this so I can't help here. Anyone who has please feel free to update here.
I got to this last part where the TCM is visible and i am not sure how this TCM comes out . It appears there are 2 screws mounted on the bracket one very high and low. The problem is both are in places very hard to reach. Do i un-mount the TCM and pull it out or do i need to unclip the TCM and then unscrew the screws ?

Thanks,
 
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