Anti-Lock Brake System: Diagnosis: INTERMITTENTS

Diagnostic charts can be used to identify problem(s), but fault must be present during testing in order to correctly locate problem. The diagnostic procedures can help determine cause of intermittent problems in ABS electrical components. Most intermittent problems are caused by faulty electrical connections or wiring.

When intermittent failure is encountered, check for trouble codes stored in ABS module. If trouble codes are found, inspect related components and circuitry for poor connections. If no trouble codes are found, inspect suspect circuits as follows:

• Check for poor mating of connector halves, or terminals not fully seated in connector body (backed-out).
• Check for improperly formed or damaged terminals. Carefully reform all connector terminals of problem circuit to increase contact tension.
• Check for poor terminal-to-wire connection. This requires removing terminal and wire from connector body for inspection. If inspection does not help locate intermittent problem, use ABS-VI self-diagnostic system to identify suspect circuit.
• Display and then clear ABS-VI trouble codes in Anti-Lock Brake Controller.
• Test drive vehicle, and attempt to duplicate conditions causing problem or complaint. Stop vehicle, and record any codes set.

Program ABS-VI Snapshot feature to identify intermittent fault. Use the Enhanced Diagnostic feature to re-create conditions causing trouble code to set. Determine how often and under what conditions fault occurs. Analyze ABS-VI Snapshot data for unusual conditions.