Intermittent Problem Diagnosis
Intermittent fault testing requires duplicating circuit or component failure to identify problem. These procedures may lead to computer setting fault code which may help in diagnosis.
If problem vehicle does not produce fault codes, use a DVOM to pinpoint faults. Monitor voltage or resistance values using DVOM while attempting to reproduce conditions causing intermittent fault. Status change on DVOM indicates area of fault.
When monitoring voltage, ensure ignition switch is in ON position or vehicle is running. When monitoring circuit resistance, ensure ignition switch is in OFF position or negative battery cable is disconnected.