Diagnostic Aids

WARNING: This page is about a different variant/trim than selected.

IMPORTANT:

Remove any debris from the PCM connector surfaces before servicing the PCM. Inspect the PCM connector gaskets when diagnosing/replacing the module. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion into the PCM.
For any test that requires probing the PCM or a component harness connector, use the J 35616 GM terminal test kit. Using this kit prevents damage to the harness/component terminals. Refer to Using Connector Test Adapters in Wiring Systems.

If the engine has sat overnight, the transmission fluid temperature and the intake air temperature values should display within a few degrees of each other. If the temperatures are not within 3°C (5°F), refer to Temperature vs Resistance in Engine Controls - 5.7L.
For an intermittent, refer to Symptoms - Engine Controls in Engine Controls - 5.7L.