Component Tests and General Diagnostics

The anti-lock brake system uses two warning indicators to alert the driver of malfunctions in the system.

The red BRAKE warning indicator will come on for only two reasons. If the brake fluid level in the master cylinder reservoir falls below the level which is determined by the set point of the fluid level switch (FLS), the BRAKE indicator will come on. Also, if the parking brake is applied, the BRAKE indicator will come on. The circuitry for this indicator is illustrated in the ABS wiring diagram.

The amber CHECK ANTI-LOCK BRAKE warning indicator will come on for numerous reasons. It warns the driver that the ABS and Traction Assist have been turned off due to a symptom that exists in the system. Normal power-assisted braking remains but the wheels can lock during a panic stop while the indicator is on. Certain procedures must be followed to find the fault in this situation.

Ensure the diagnostic procedures are followed step-by-step in order as indicated.

WARNING: FOLLOWING THE WRONG SEQUENCE OR BYPASSING STEPS WILL LEAD TO UNNECESSARY REPLACEMENT OF PARTS, AND/OR INCORRECT RESOLUTION OF THE SYMPTOM.

The diagnostic procedure consists of five sections:

1. Pre-Test Check

2. On-Board Diagnostics

3. Manual Quick Tests

4. Warning Indicator Symptom Chart

5. Diagnostic Tests (including electrical schematics)