Diagnosis & Testing: INTERMITTENTS

Failures in anti-lock brakes may be difficult to diagnose accurately. If an intermittent condition is being diagnosed, ABS self-diagnosis system can help find suspect circuit.

• Display and clear any ABS trouble codes present in EBCM.
• Test drive vehicle. Attempt to repeat failure condition. Getting a description of the driving conditions when failure occurred can help.
• After duplicating condition, stop vehicle and access ABS trouble codes.
• If no trouble codes were stored, it may be necessary to use symptom diagnosis.

Most intermittent problems are caused by faulty electrical connectors or wiring. When an intermittent failure is encountered, check suspect circuits for:

• Poor connector or terminal mating in connector body (backed out).
• Improperly formed or damaged terminals. All connector terminals in a problem circuit should be carefully reformed to increase contact tension.
• Poor terminal to wire connection. This requires removing terminal from connector body to inspect.
• Wheel speed sensor cables not attached in retainers or routed too close to spark plug wires.
• Low system voltage. If low system voltage is detected at EBCM, the ABS will turn on the ANTI-LOCK light until normal system voltage is achieved.