Vehicle Identification (VID) Block
The PCM contains a memory area called a vehicle identification (VID) block. A portion of the VID block is used to store the backup data for each programmable module on the vehicle.
The VID block is the first backup of information when using the PMI configuration method. If the diagnostic tool cannot retrieve option content information from the suspect module, the diagnostic tool will attempt to extract backup information from the VID block of the PCM.
The VID block is not related to or affected by the powertrain calibration information stored in the PCM. If a new powertrain calibration has been flashed onto the PCM, the VID block will not be affected.
If using the PMI routine to install a new PCM, the diagnostic tool will reprogram only VID information. The engine calibration information may still need to be flashed. For more information, refer to the SELF-DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE for flash programming information.