Intermittent Problem Diagnosis

Intermittent fault testing requires duplicating circuit or component failure to identify problem. These procedures may lead to computer setting a Diagnostic Trouble Code (DTC) on some systems, which may help in diagnosis.

If problem vehicle does not produce DTCs, monitor voltage or resistance with DVOM while attempting to reproduce conditions causing intermittent problem. A status change on DVOM indicates a problem has been located.

Use a DVOM to pinpoint problems. When monitoring voltage, ensure ignition is on or engine is running. Ensure ignition is off or negative battery terminal is disconnected when monitoring circuit resistance. Status changes on DVOM during test procedures indicate area of problem.