With Vehicle Control Module (VCM)

Vehicle Control Module (VCM):

DESCRIPTION
The Vehicle Control Module (VCM) is located on the right hand side fenderwell, is the control center for the fuel emissions and antilock brake systems.

OPERATION
The VCM constantly monitors the information from various sensors and controls the component systems which affect engine and. antilock operation. The VCM also performs the diagnostic function of the system. The VCM can alert the driver through the Malfunction Indicator Lamp (MIL) Service Engine Soon or anti-lock indicator lamp and store one or more Diagnostic Trouble Codes (DTCs) which can identify the problem areas to aid the technician in making repairs. Refer to Testing and Inspection for further information on using the diagnostic function of the VCM, for engine operation. Refer to Brakes and Traction Controls/Antilock Brake System for further information on antilock brakes.

Programming VCM
The VCM in this vehicle is programmable. The only services allowed on the VCM is control module replacement with PROM transferred or PROM only. The PROM contains the operational software, backup fuel calibrations, and the up integrated knock sensor circuit. The calibrations are stored in the VCM in the Electronically Erasable Programmable Read Only Memory (EEPROM). When replacing the VCM, it will be mandatory to program the EEPROM and transfer the PROM to the new VCM. Refer to Service and Repair VCM Replacement. Service and Repair

Calibrating VCM
The four calibrations required for the VCM are engine, Antilock Brake System (ABS), Vehicle Speed Sensor (VSS) buffer and A/C. Each calibration will have its own part number. Determination of the correct calibrations for a particular vehicle will be based on the VIN number of the vehicle.