Intermittent and History DTCs

History DTCs are codes that indicate that the BCM detected a fault which has disappeared.

Any DTC that begins with the digit 3 is a history DTC.

The fault will be stored as a history code under either of the following conditions:
^ The fault is an intermittent failure.
^ The fault exists in a system which is not currently being operated.

If you cannot determine the cause of the failure through visual inspection, complete the following steps:
1. Connect a DVM to the suspected circuit.
2. Drive the vehicle.
3. Observe the readings. An abnormal voltage or resistance reading when the failure occurs indicates that the condition may be in the suspected circuit.