Inspection and Verification - Drive Cycle Test

Inspection and Verification - Drive Cycle Test
The drive cycle test can be used as a system evaluation test or repair verification test, or during diagnosis (for intermittent concerns).

For system evaluation, the customer may only have a general concern about the way the vehicle is braking, There may not be a clear system concern to troubleshoot. This test is designed to produce common system concern symptoms. Once a symptom is found, a symptom diagnostic procedure can be followed to repair the vehicle.

Always use this test after vehicle repairs because the anti-lock brake control module is unable to detect some system concerns unless the vehicle is driven under specific conditions. After completing the drive cycle test, carry out the self-test using New Generation STAR (NGS Tester.

NOTE: Wetting down the area where the stops are to be performed will aid in this test.

NOTE: An assistant should be used to monitor the wheels during the ABS stop. Momentary lockup is permissible.

1. While driving the vehicle approximately 16 km/h (10 mph), depress the brake pedal hard enough to lock all four wheels.
2. Does one wheel lock consistently?
- If yes and the yellow ABS warning indicator is not illuminated, proceed to the Symptom Chart. Symptom Related Diagnostic Procedures
- If yes and the yellow ABS warning indicator is illuminated, retrieve and document DTCs. Proceed to Anti-Lock Brake Control Module Diagnostic Trouble Code (DTC) Index. Diagnostic Trouble Code Tests and Associated Procedures

3. NOTE: If the pump motor turns on and the vehicle pulls immediately, the front anti-lock brake sensor opposite the pull should be checked using the ABS Misfire, ABS Too Sensitive, ABS Fires On Normal Stop procedure from the Symptom Chart. If the pump motor turns on and the vehicle does not pull, the rear anti-lock brake sensors should be checked using the ABS Misfire, ABS Too Sensitive, ABS Fires On Normal Stop procedure from the Symptom Chart. If the pump motor does not turn on and the vehicle pulls immediately, the system should be checked using the Vehicle Pulls During Braking procedure from the Symptom Chart. Symptom Related Diagnostic Procedures

NOTE: Turn off the windshield wipers.

While driving the vehicle approximately 32 km/h (20 mph), perform a light-to-medium (normal traffic) stop.
4. Does the pump motor turn on and are brake pedal pulsations felt at any time during the stop?
- If yes and the yellow ABS warning indicator is not illuminated, proceed to the Symptom Chart. Symptom Related Diagnostic Procedures
- If yes and the yellow ABS indicator does illuminate, retrieve and document DTCs. Proceed to Anti-Lock Brake Control Module Diagnostic Trouble Code (DTC) Index. Diagnostic Trouble Code Tests and Associated Procedures
5. C1ear continuous DTCs.
6. Start the vehicle and shift the transmission into low gear.
7. Allow the vehicle to creep forward at idle for at least 45 seconds.
8. Does the yellow ABS indicator illuminate?
- If yes, retrieve and document DTCs. Proceed to Anti-Lock Brake Control Module Diagnostic Trouble Code (DTC) Index. Diagnostic Trouble Code Tests and Associated Procedures
9. Slowly accelerate to 40 km/h (25 mph). Let at least 45 seconds elapse before reaching 40 km/h (25 mph).
10. Does the yellow ABS warning indicator illuminate?
- If yes, retrieve and document DTCs. Proceed to Anti-Lock Brake Control Module Diagnostic Trouble Code (DTC) Index. Diagnostic Trouble Code Tests and Associated Procedures
11. Has the customer concern been addressed and corrected by the previous actions?
- If yes, the system is OK.
- If no, proceed to the Symptom Chart. Symptom Related Diagnostic Procedures