Transmission Control Module (TCM) Location and Access *

[CoolVanilla]

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.

[Dookie]

EXCELLENT post and pics CV...and 100% accurate.

BTW...you should get a call about your injectors.

[kentc1978]

Nice writeup

Not to take this off topic, but what are those buttons above your brake release for?

[Bubba's Dragon]

yep yep are those the hyperdrive, mounted to low for machine guns, lets all guess.. hmm trunk release, maybe... crap I forgot the sonic front blasters from the headlights!!!

[CoolVanilla]

The left one deployes these:



The right one... well if I told you...

[Meister]

Outstanding post, CV. And your timing is exquisite.

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...

[jay2puff]

Great post and pics Coolvanilla

[InferAl]

Outstanding post, CV. And your timing is exquisite.

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...

If it was installed at the dealer do you think they would have manually stored the addaptives with the starscan tool ?

[Meister]

If it was installed at the dealer do you think they would have manually stored the addaptives with the starscan tool ?

I would hope so - they should have.

As you can see from the excerpt from the service manual, it is standard practice to do so with a new TCM.

[InferAl]

I would hope so - they should have.

As you can see from the excerpt from the service manual, it is standard practice to do so with a new TCM.

Thanks, I would hope so too. He was thier best trained tech with the computer stuff. My nephew is a tech at a Chysler dealer and I am always telling him stuff he doesn't know about these cars. Its hard sometimes when you go to dealers and have to tell them things they never heard of, it makes you kind of uneasy

[Meister]

...Its hard sometimes when you go to dealers and have to tell them things they never heard of, it makes you kind of uneasy

One of the hazards of forum life, InferAl.

[InferAl]

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]

[CoolVanilla]

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.

[RPMSRT8]

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...

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]

Will the second TCM stay in next to the original be secure enough just sitting in there ?...

As long as you replace the dash panel before gettin on it too hard, IA, it's not going anywhere.