Intermittent Problem Diagnosis
Intermittent fault testing requires duplicating circuit or component failure to identify fault. These procedures may lead to computer setting a diagnostic trouble code which may help in diagnosis.
If problem vehicle does not produce diagnostic trouble codes, monitor voltage or resistance values using a DVOM while attempting to reproduce conditions causing the intermittent fault. A status change on DVOM indicates a fault has been located.
Use DVOM to pinpoint faults. When monitoring voltage, ensure ignition is in ON position or engine is running. When monitoring resistance, ensure ignition switch is in the OFF position or negative battery cable is disconnected. A status change on DVOM while performing TEST PROCEDURES indicates area of fault.