Intermittent Problem Diagnosis

Intermittent problems may cause a noticeable driveability problem or cause the "CHECK ENGINE" to illuminate. Before attempting to diagnose an intermittent fault, ensure steps in BASIC TESTING and TESTS W/CODES (if applicable) have been performed. Intermittent fault testing requires duplication of circuit or component failure in order to identify the fault. These procedures may cause the computer to record a fault code which may help in diagnosis.

If the vehicle's problem does not produce fault codes, it will be necessary to monitor voltage or resistance values using a DVOM while attempting to produce conditions which will create an intermittent fault. A change in status on the DVOM will indicate a fault has been located.