Intermittent Conditions

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.

Notes on System Circuit Inspection

Notice: In order to prevent internal damage to the PCM, the ignition must be OFF when disconnecting or reconnecting the PCM connector.

^ Most intermittent malfunctions are caused by faulty electrical connections or faulty wiring. Perform a careful check of the suspect circuits for any of the following conditions:
- Poor mating of the connector halves.
- Electrical terminals that are not fully seated into the connector body (backed out).
- Improperly formed or damaged terminals. All connector electrical terminals in malfunctioning circuits should be carefully reformed in order to increase contact tension.
- A poor terminal to wire connection.
^ Use the J 39200 Digital Multi meter or a equivalent whose minimum resistance is more than one mega ohm per volt. Other Digital Multimeters should not be used because accurate measurements may not obtained.
^ When checking the voltage at each terminal of the connector while it is connected to the PCM, be sure to connect the negative probe to the body ground and use a jumper wire to connect the positive probe to the connector terminal being tested. Applying the electrical probes of the Digital Multimeter improperly may cause a sensor or the PCM to be shorted and damaged.