Intermittent Problem Diagnosis

Intermittent fault testing requires duplicating circuit or component failure to identify problem. These procedures may lead to computer setting a fault code which may help in diagnosis.

If problem vehicle does not produce fault codes, monitor voltage or resistance values using Digital Volt-Ohmmeter (DVOM) while attempting to reproduce conditions causing intermittent fault. Abnormal status changes on DVOM indicate a fault has been located.

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