Intermittent Malfunctions

There are cases where the Malfunction Indicator Lamp (MIL) indicates that a DTC representing a fault, which occurred only temporarily, has gone away.

In such instances good parts are sometimes replaced unnecessarily. In order to prevent such an error, be sure to follow the instructions given below when using the diagnostic tables.

When a malfunction can be identified, that is, it is not an intermittent fault, check the sensor (actuator), wires and each connection in order to make sure that they are all in good condition.

When a malfunction cannot be identified, but the MIL indicates a DTC:
^ Diagnose the malfunction by using the appropriate DTC chart. If the sensor (actuator), the wires, and the electrical connections are all in good condition, erase the DTC from the PCM memory. Conduct a test run and check what DTCs are present when the MIL illuminates. The malfunction is present only when the MIL indicates a DTC again.
^ First time occurrences of Type B DTCs will store in the Test Failed Since Code Cleared (Test Fail SCC) scan tool display but not in the History display. When the MIL is ON and a DTC is indicated in the History display, a current fault is indicted.