Engines & PCMs, Trans & TCMs: Exact part number matching is mandatory

[dtennes]

For those of you who have...

A. Contemplated replacing the existing engine in your vehicle
B. Actually gone ahead and done what you THINK is an effective engine replacement
C. Contemplated using a new, non-stock engine to upgrade/replace your existing stock engine
D. Replace your PCM for whatever reason

Note the following:

There is a very specific matching of engine, PCM, transmission, and TCM that must be attended to. If you ignore this, you are letting yourself in for a whole lot of headaches, wasted time and wasted money.

I am attaching a Chrysler PCM/TCM/BCM calibration list that I stumbled across somewhere this morning. Unfortunately, I copied the doc to my PC with a new filename that made sense in plain english, and then accidentally closed the browser session before copying the URL that pointed to it. If I can find it again I will add that link to this post.

What this list will show you is the nit-picking matching of 100s of specific matches. If you stray from the explicit matching part numbers that are specific to your stock vehicle, you are screwed.

If anyone out there refutes that statement, let's hear it. Examples of 100% success in using mismatched engines/pcms/transmissions/tcms is a very interesting scenario and I would really like to do some q&a with anyone that pulled that off with 100% success. From what I can see in the documentation such a scenario should be impossible.

Anyway, my stock vehicle spec consists of "2003 KJ 3.7L AUTO NLEV" calibration, relative to an original PCM part number "56044195AG", with a matching "2003 KJ 3.7L EATX3B" calibration relative to an original TCM part number "56044192AE". American market KJ with 3.7L and 4wd 42RLE. That will give you all the search criteria needed to sift through the attachment to understand how specific this matching thing is.

The really intimidating thing is that if you search for the newest "new part" variations for either of those parts (56044195AH and 56044195AH respectively) you will not find them anywhere else in the list, which means its that specific part or you end up with all kinds of troubleshooting issues when nothing works correctly... if you can even get the vehicle started with mismatched parts.

 

[dtennes]

Remember, the PCM talks to the TCM constantly and vice-versa. Mismatched PCMs and TCMs will not communicate correctly. This problem cascades to the physical engine and trans... so trying to drop a manual trans into a vehicle originally equipped with an auto 45RFE or 42RLE is a hot mess.

Btw, 2002 KJs don't have a TCM, they have a BCM.

If that statement is off-base, please refute with useful information to help out. Thanks.

 

[CheddarGau]

Needing to have vin programmed into the PCM, TCM, BCM, etc is nothing new. Part number refers to a couple things on Chrysler vehicles. Parts number can be a combination of the physical hardware and the software (based on vehicle configuration). So part numbers for equipment (PCM for example) can change as hardware supersedes older variants. The important thing is that the hardware is compatible with the hardware/software (a 2.4L PCM is not compatible with a 3.7L vehicles)it must communicate with, which is why VIN's must be programmed into the new hardware you are installing (such as a new PCM). This is why you can buy a rebuilt PCM, provide your VIN and you receive the new hardware and it just plugs in and works. So in general (there are always exceptions and only referring to chyrsler) if you have a (used) PCM from the exact same configured vehicle (matching trans/engine, etc), write your vin to the PCM, you will have a functioning vehicle. You mileage could be wrong, when you view the data of the pcm (along with some other info in hardware detail), and part numbers might not be correct, but it will work. The key is matching vehicle configuration, or else writing the vin to the new hardware won't work.

Now 2002-2004 Liberty are using the older Chrysler system (DRB 3), while 2005+ use a computer system, thats compatible witech system. That hardware/software is not compatible with each other. The reason is, the computer system is totally different. Chrysler Witech 2 can largely not communicate with the older vehicles and must reply on the DRB 3 or the DRB3 emulator software. So despite having all the same configuration, the computer system is simply different and will not work with each other.

Also it is not common for BCM to be in control of anything power train related. Typically that is the PCM or TCM. However you will often see that the TCM will be integrated to the PCM(but not always).

BCM can be your gateway, but usually does not directly control (there are always exceptions, but that is not a common set up). BCM usually handles everything body related, such as lights, doors, windows, etc. Below you will see there is a TCM in the 2002 vehicles. It could be within the PCM physically, but it is there.

You must be registered for see images attach

You must be registered for see images attach

 

[joshgoble]

For those of you who have...

A. Contemplated replacing the existing engine in your vehicle
B. Actually gone ahead and done what you THINK is an effective engine replacement
C. Contemplated using a new, non-stock engine to upgrade/replace your existing stock engine
D. Replace your PCM for whatever reason

Note the following:

There is a very specific matching of engine, PCM, transmission, and TCM that must be attended to. If you ignore this, you are letting yourself in for a whole lot of headaches, wasted time and wasted money.

I am attaching a Chrysler PCM/TCM/BCM calibration list that I stumbled across somewhere this morning. Unfortunately, I copied the doc to my PC with a new filename that made sense in plain english, and then accidentally closed the browser session before copying the URL that pointed to it. If I can find it again I will add that link to this post.

What this list will show you is the nit-picking matching of 100s of specific matches. If you stray from the explicit matching part numbers that are specific to your stock vehicle, you are screwed.

If anyone out there refutes that statement, let's hear it. Examples of 100% success in using mismatched engines/pcms/transmissions/tcms is a very interesting scenario and I would really like to do some q&a with anyone that pulled that off with 100% success. From what I can see in the documentation such a scenario should be impossible.

Anyway, my stock vehicle spec consists of "2003 KJ 3.7L AUTO NLEV" calibration, relative to an original PCM part number "56044195AG", with a matching "2003 KJ 3.7L EATX3B" calibration relative to an original TCM part number "56044192AE". American market KJ with 3.7L and 4wd 42RLE. That will give you all the search criteria needed to sift through the attachment to understand how specific this matching thing is.

The really intimidating thing is that if you search for the newest "new part" variations for either of those parts (56044195AH and 56044195AH respectively) you will not find them anywhere else in the list, which means its that specific part or you end up with all kinds of troubleshooting issues when nothing works correctly... if you can even get the vehicle started with mismatched parts.

Depending on the year and your equipment you can edit the PCM and TCM an match the parameters to what is needed. If you cannot get the factory PCM to flash over to the parameters you need then you can purchase one that is programmable and user friendly and can adapt just about any type of parameter needed. The computer's side of it's actually fairly easy they're all written with the same language depending on what it is I think Chrysler products are all written in C or MISRA-C (Motor Industry Software Reliability Association C. I think don't quote that with our double checking.

ECU software can be written in assembler, C, Pascal, C++, Ada or, probably, Fortran. Assembler and C are likely the most popular, with C++ also being used.

 

[dtennes]

What Josh noted is truth. FS1 uses "universal" PCMs that have been appropriately flashed per VIN. VIN is key.