How to Install a Used PCM (GPEC2/GPEC2A) Without the Original Module
After moving to the USA from Ukraine in 2019, I have been working as a truck driver in Cleveland, Ohio. Before that, I worked in automotive electronics for 20 years.
A mechanic in our company bought a 2018 Dodge Charger with a 6.4L engine, but its PCM (GPEC2A) was stolen. He purchased a used PCM, but installing it in the car turned out to be a major problem!
What’s the Issue?
There is no clear information on how to synchronize a used PCM with the immobilizer (RFHUB/BCM). Even expensive tools like Autel IM608 do not support this function. The ECUHERO software can clone these PCMs but does not allow installing a used one without the original.
The mechanic sent the PCM twice to a specialized company that handles these issues, but they were unsuccessful.
My Solution
I decided to investigate where the synchronization bytes between the PCM, BCM, and RFHUB are stored, and it turned out to be quite simple.
I contacted the support teams of several programming tool manufacturers to request this function (installing a used PCM without the original), but they did not respond. It is surprising that even high-end tools cannot perform such a simple operation.
For example, OBDSTAR DC706 can clone RFHUB but does not allow installing a used PCM. However, all that is needed is to read 6 bytes and write them into the PCM in Bench Mode!
How to Install a Used PCM GPEC2/GPEC2A
If you own a Dodge Charger, Challenger, RAM, or another vehicle with GPEC2/GPEC2A, and you need to replace the PCM ? give this information to a specialist who works with processor programmers.
Steps to Follow:
1. Read EEPROM 95640 from GPEC2A.
2. Read the microcontroller MC9S12XEG384 in RFHUB or SPC5606 in BCM.
3. Find the 6 bytes in the RFHUB module and write them into the PCM.
4. Optionally, write the VIN (it repeats three times).
If you are working with BCM, the 6 bytes are stored in a mirrored layout.
What’s in the Archive?
I have prepared an archive that contains:
✅ Three files with the necessary 6 bytes (the filenames will indicate the address and synchronization bytes).
✅ Three images showing where these bytes are located.
https://dropmefiles.com/BMVcJ
Archive password: 123
Archive password: city_Boryslav
This method allows you to quickly install a used PCM without needing the original. I am sharing this solution to help both specialists and car owners who face this problem.
If you have any questions or need more details ? feel free to ask!