Basic Knowledge Required

PCM Diagnosis
The Powertrain Control Module (PCM) is an advanced electronic component that requires careful handling and diagnosis. The PCM can be damaged by improper testing procedures or equipment. The PCM's performance can be affected by the use and operation of other components.

Service of the PCM consists of the replacement and reprogramming of the PCM. The PCM has no serviceable parts, but does contain an erasable programmable read only memory (EPROM) chip that requires recalibration. Replace the PCM as a complete assembly if the PCM is determined to be faulty.

Basic Knowledge Of Tools Required

Notice: Lack of basic knowledge of this powertrain when performing diagnostic procedures could result in incorrect diagnostic performance or damage to powertrain components. Do not attempt to diagnose a powertrain problem without this basic knowledge.

A basic understanding of the proper use of hand tools is necessary in order to effectively use this information.

Use Of Circuit Testing Tools
DO NOT use a test lamp to diagnose powertrain control electrical Systems unless specifically instructed to do so by the diagnostic procedures. Use the J 35616-A Connector Adapter Kit or an equivalent whenever the diagnostic procedures call for probing any connectors.

PCM Service Precautions

Notice: 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 or an equivalent. The PCM electrical connectors should remain connected to the PCM during testing.