Vehicle Identification (VID) Block
WARNING: This page is about a different car, the 2003 Ford Windstar. However, it is still accessible from the selected car via links, so may be relevant.
Some PCMs contain a memory area called a vehicle identification (VID) block. The VID block is used to store backup data for each programmable module, as well as powertrain configuration information.
If the diagnostic tool cannot retrieve module option content information from the suspect module, the diagnostic tool will attempt to extract backup information from the PCMs VID block.
The PCM VID block contains the factory settings for the configurable modules unless the PCM is flashed with a new calibration in which case some PCM parameters may be modified.