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 (on some systems) which may help in diagnosis.

If problem vehicle does not produce fault codes, use DVOM to pinpoint faults. Monitor voltage or resistance values while attempting to reproduce conditions causing intermittent fault. A status change on DVOM indicates area of fault.

When monitoring voltage, ensure ignition switch is in ON position or engine is running. Ensure ignition switch is in OFF position or negative battery cable is disconnected when monitoring circuit resistance.