Diagnostic Aids

For any test that requires probing PCM or component harness connectors, use Connector Test Adapter Kit (J-35616-A). This will prevent damage to harness connector terminals.

Check for skewed TP or ECT sensor. A faulty TP or ECT sensor or sensor circuit can cause PCM to incorrectly calculate predicted mass airflow value.

Check for poor connections at PCM or at component. Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals and poor terminal-to-wire connections.

Check for misrouted wiring harness. Inspect harness to ensure that it is not routed too close to high voltage wires (spark plug wires) or too close to high current devices (generator, motors, solenoids).

Check for damaged wiring harness. If harness appears to be okay, observe scan tool while moving related connectors and wiring harnesses. A change in scan tool display may help to locate fault. If sensor signal is only affected when harness is moved at a component, and there is no problem with wiring harness or connections, component may be faulty.