P1639 FORD - Vehicle ID Block Corrupted or Not Programmed
Possible causes
- New PCM-Needs programming
- Incorrect VID configuration
As part of the calibration there is an area referred to as the Vehicle Identification (VID) block. The VID block must be programmed when replacing the PCM as described under Programming the VID Block for a Replacement PCM. Failure to perform this procedure may generate fault codes: P1635, P1639, VID Block not programmed or is corrupt. The VID block in an existing PCM can also be tailored to accommodate various hardware/parameter changes made to the vehicle since production. Failure to perform this procedure properly may generate fault code: P1635, Tire/Axle Ratio out of Acceptable Range is one of the main causes for code: P1639. This is described under Making Changes to the VID Block and also under Making Changes to the PCM Calibration. The VID block contains many items used by the strategy for a variety of functions. Some of these items include the VIN number, octane adjust, fuel octane, fuel type, vehicle speed limit, tire size, axle ratio, the presence of speed control and four wheel drive electronic shift on the fly versus manual shift on the fly. Only items applicable to vehicle hardware and supported by the VID block will be displayed on the scan tool.