The VCM is located on the right hand side fenderwell. The VCM is the control center for the fuel emissions automatic transmission control functions and the antilock brakes systems.

The VCM constantly monitors the information from the various sensors. The VCM controls the component systems which affect the engine, the transmission, and the antilock operation.

The VCM alerts the driver through the Malfunction Indicator Lamp (MIL) or the antilock indicator lamp. The VCM stores the DTCs which identify the problem areas for the technician making repairs. Refer to Vehicle Control Module (Serial Data Communication) , for further information on using the diagnostic function of the VCM for engine operation.

Refer to Transmission for the diagnosis of the automatic transmission. Refer to Section 5E3B in the appropriate service manual for further information on the antilock brakes.

The VCM in this vehicle is programmable. The only services allowed on the VCM is the control module replacement with the KS calibrator PROM transferred or the KS calibrator PROM only.

The KS calibrator contains the up integrated knock sensor calibration. The VCM stores the 4 calibrations in the Electronically Erasable Programmable Read Only Memory (EEPROM).

When replacing the VCM, programming the EEPROM and transferring the KS calibrator PROM to the new VCM is mandatory. Refer to the EEPROM Programming .

The 4 calibrations required for the VCM are the Powertrain, the ABS, the VSS buffer, and the A/C. Each calibration has its own part number. Determine the correct calibrations for a particular vehicle based on the VIN number of the vehicle.

The VCM processes the various input information. The VCM sends the necessary electrical responses to the control fuel delivery, the spark timing, and the other emission control systems. The input information interrelates to more than one output; therefore, if the one input fails, the failure can affect more than one system.

Notice: Since the VCM is located under the hood, its connectors are sealed and cannot be backprobed as in the previous model years. Do not attempt to backprobe as a connector or seal damage could occur.

The learning ability of the VCM allows the VCM to make corrections for minor variations in the fuel system in order to improve driveability.

When the battery is disconnected for other repairs, the learned connections are lost. The driver may note a change in the performance of the vehicle. The engine must be at normal operating temperature for learning to occur. Drive the vehicle at part throttle with a moderate acceleration and idle condition until the normal performance returns.