How do I change the VIN in a PCM?

[WhisperPC]

I've been tuning a PCM, and it decided to fail (no spark output). I got a replacement PCM, but the VIN in it is different. How do I use EFILive to change the VIN to match the vehicle?

[joecar]

Scantool: go Bidirectional->Change VIN


But, to flash the tune file to the new PCM you will need to use a new license (licences are based on PCM serial number not VIN).

[SMOKINV8]

Bumping a slightly old thread here. If I just needed to change the VIN to satisfy the immobilizer system on an E40 car, would I need to license the PCM? I'm assuming no, since this is done through the scan tool. A little peace of mind would be nice before the car is back.

[DURAtotheMAX]

Are you sure you need to change the VIN?

It wasnt until the the Global-A electrical system generation vehicles that VIN really mattered and was shared between modules for anti-theft purposes.

Most of the time before that, and during the E40-era, as long as the security pre-learned password (a 2-byte 0-65,535 value), known/learned only by the theft deterrent module/BCM and the ECM) from the immobilizer system and immobilizer challenge/response matches what is stored in the ECM, it doenst really care what the actual VIN is.

Try a manual anti-theft relearn, or a forced-relearn with a scan tool first, because I THINK you have to burn a license in order to update VIN.

[SMOKINV8]

The short answer is no, I'm not sure I need to change the VIN. I know that right now the car immediately trips a P1677 (think that's correct, haven't slept much) DTC as soon as the vehicle starts. As a temporary fix I shit the code off and all is well enough, but I understand that this guy will want everything "right."

I've been primarily an HPTuners guy for a long long time, but neither the VIN change nor relink procedure would work with that software on this car. It's an 05 GTO, and the replacement ECM was apparently bought from a junkyard Ranier. Figured this would be a good time to put my EFILive to use for more than my truck if it'll resolve my issue.

[joecar]

The ECM should still have the correct VIN written to it for various reasons (even if it is not necessary)...

scantool does not require any license to write the VIN to the ECM.

[SMOKINV8]

Great, thank you!

[DURAtotheMAX]

ah ok.

The GTO might be different with the immobilizer and VIN requirements since its based on an Australian platform, and not something "north american". I know there are some unique things on the BCM/databus side of the GTO that dont follow traditional GM north american design rules in regards to systems integration and all that.

[SMOKINV8]

I'm crossing my fingers a little, I'm basically running through things one at a time that could be throwing the code and there's only a couple things left. I suspected doing a complete write would take care of the relink, but I don't have confirmation on that. Thanks for contributing though, I know you work a little deeper in this stuff than I do.