Diagnostic Strategies
INTERMITTENTS AND POOR CONNECTIONSAs with most electronic systems, intermittent malfunctions may be difficult to accurately diagnose. The following is a method to try to isolate an intermittent malfunction, especially wheel speed circuitry. If an ABS malfunction occurs, the amber ABS indicator lamp will be ON during the ignition cycle in which the malfunction was detected. If it is an intermittent problem which seems to have corrected itself (amber ABS indicator lamp OFF), a diagnostic trouble code will be stored. Also stored will be the history data of the DTC at the time the malfunction occurred. The scan tool, such as the Tech 2, must be used to read DTC history data. Most intermittents are caused by malfunctioning electrical connections or wiring.