Intermittent failures in electronic systems may be very difficult to detect and accurately diagnose. The instrument cluster tests for different malfunctions under different vehicle conditions. For this reason a thorough test drive is often needed in order to repeat a fault condition. If the system malfunction is not repeated during the test drive, a good description of the complaint may be useful in locating an intermittent fault condition. Faulty wires or connections cause most intermittent problems. When an intermittent condition is suspected, inspect the suspected circuits for the following condition:

History diagnostic trouble codes (DTCs) indicate that the instrument cluster has previously detected a malfunction. The reason may be either that the malfunction is intermittent, or that the system for which the DTC is set for is not currently being operated. If the instrument cluster displays history DTCs, and the malfunction cannot be found easily, clear the DTCs and manually operate the system that the DTC applies to using a scan tool. Read the Diagnostic Aids and Conditions for Setting the DTC in each DTC table for more specific information.

History DTCs help in diagnosing intermittent fault conditions, but do not necessarily indicate a faulty instrument cluster. Most system complaints are linked to faulty wiring and connectors, and occasionally to a component. Perform a thorough inspection of all related wiring and connectors pertaining to the history DTC that is stored: