ABS Vehicle Test Drive

ABS VEHICLE TEST DRIVE

Most Antilock Brake System (ABS) complaints will require a test drive to properly duplicate and diagnose the condition.

WARNING: CONDITIONS THAT RESULT IN TURNING ON THE RED BRAKE WARNING INDICATOR MAY INDICATE REDUCED BRAKING ABILITY.

Before test driving a brake complaint vehicle, note whether the red BRAKE warning indicator, amber ABS warning indicator, or both are turned on. If it is the red BRAKE warning indicator, there is a brake hydraulic problem that must be corrected before driving the vehicle. Refer to the BASE BRAKE SYSTEM for diagnosis of the red BRAKE warning indicator. If the red brake warning indicator is illuminated, there is also a possibility that there is an ABS problem and the amber ABS warning indicator is not able to illuminate, so the Mechanical Instrument Cluster (MIC) turns on the red Brake warning indicator by default.
If the amber ABS warning indicator is on, test drive the vehicle as described below. While the amber ABS warning indicator is on, the ABS is not functional. The ability to stop the car using the base brake system should not be affected.
If a functional problem of the ABS is determined while test driving the vehicle, refer to the Diagnostic Procedures.
1. Turn the key to the OFF position and then back to the ON position. Note whether the amber ABS warning indicator continues to stay on. If it does, refer to the diagnostics.
2. If the amber ABS warning indicator goes out, shift into gear and drive the car to a speed of 25 km/h (15 mph) to complete the ABS start-up and drive-off cycles. If at this time the amber ABS warning lamp comes on, refer to the diagnostics.
3. If the amber ABS warning lamp remains out, drive the vehicle a short distance. Accelerate the vehicle to a speed of at least 64 km/h (40 mph). Bring the vehicle to a complete stop, braking hard enough to cause the ABS to cycle. Again accelerate the vehicle past 40 km/h (25 mph).