PCM Service Precautions

NOTE: Turn the ignition OFF when installing or removing the PCM connectors and disconnecting or reconnecting the power to the PCM (battery cable, PCM pigtail, PCM fuse, jumper cables, etc.) in order to prevent internal PCM damage.

IMPORTANT: Before replacing the Powertrain Control Module (PCM) make sure that the PCM contains the correct calibrations for the model, equipment, and year of the vehicle being serviced. A PCM incorrectly programmed, or with the wrong calibrations, can set false or incorrect DTCs. Incorrect calibrations can also cause driveability symptoms and concerns.

The Powertrain Control Module (PCM) is designed to withstand normal current draws associated with vehicle operations. Avoid overloading any circuit. Do not ground or apply voltage to any of the PCM circuits unless instructed to do so. Do not apply voltage to any of the PCM circuits when testing for an open or a short in an electrical circuit. The PCM circuits should only be tested using the J 39200 Digital Multimeter (DMM) or an equivalent. The PCM electrical connectors should remain connected to the PCM during testing.