Operation CHARM: Car repair manuals for everyone.

PCM Service Precautions

The PCM is designed to withstand normal current draws associated with vehicle operations, however, care must be used to avoid overloading any of these circuits. In testing for opens or shorts do not ground or apply voltage to any of the PCM circuits unless instructed to do so by the diagnostic procedures. These circuits should only be tested using the DMM.

Whenever a PCM removal and replacement is performed, follow the procedures.