(NOTE: The information below is for informational purposes only. Follow at your own risk!)
(special thanks to GNXClone from LS1GTO for this information! )
We had a 2005 Pontiac GTO that rolled in with a unique issue: The owner had replaced the BCM and was unable to start due to VATS being activated. Simple enough? Not so on these. The BCM needs to be security-linked to the PIM (Powertrain Interface Module) on these cars, but requires a 6-digit PIN code in order for GM’s SPS software to link. Since this was a used BCM and the PIN code or VIN was long gone, most consider it a “lost cause” short of consulting the dealership (which in our experience has been spotty at best). Not so! We were able to retrieve the PIN by reading it directly from the BCM by doing the following below:
First, we remove the BCM from its mounts (underneath the glovebox on the passenger side):
Next, we expose the BCM’s circuitry on our workbench (excuse the mess!). This particular BCM snaps together, so (dis)assembly was easy.
This particular chip is our target. It is a serial I2C EEPROM (Flash Memory) that contains the configuration information for the BCM, including our security PIN:
Using a hot-air rework tool, the EEPROM is removed. Take care not to overheat it as it may result in damage to the data stored on it!
The EEPROM is now soldered onto the reader adapter and placed into the reader:
After reading, we are presented with the data below. For this particular BCM, the security pin is stored at 0x52-0x53 and is byte swapped.
In this example, the data is stored as 0x4AAF but the PIN is actually “read” as 0xAF4A.
Translating this from hex to decimal, the PIN for this particular BCM is 044874:
After this, the EEPROM is now resoldered to the BCM, then the BCM is reassembled and reinstalled into the car.
To complete this repair, the BCM was then re-linked to the PIM using a Tech2 (Tech2Win and a J2534 interface can be used in place of one):
This is but one of the successful odd jobs we have done. Feel free to contact us with your unique needs!