Inspection and Verification - Drive Cycle Test

Inspection and Verification - Drive Cycle Test
The drive cycle test can be used as a system evaluation test, a 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 ABS 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 the scan tool.

NOTE: Wetting down the area where the testing is to be carried out 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), press the brake pedal hard enough to lock all 4 wheels.
2. Does one wheel lock consistently?
^ If yes and the yellow ABS warning indicator is not illuminated, GO to Symptom Chart. Symptom Chart
^ If yes and the yellow ABS warning indicator is illuminated, retrieve and document the DTCs. Proceed to the ABS Module DTC Chart. ABS Module DTC Chart
3. 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, GO to Symptom Chart. Symptom Chart
^ If yes and the yellow ABS indicator is illuminated, retrieve and document DTCs. Proceed to the ABS Module DTC Chart. ABS Module DTC Chart
5. Clear 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 the DTCs.
^ Proceed to the ABS Module DTC Chart. ABS Module DTC Chart
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 the DTCs.
^ Proceed to the ABS Module DTC Chart. ABS Module DTC Chart
11. Has the customer concern been addressed and corrected by the previous actions?
^ If yes, the system is OK.
^ If no, GO to Symptom Chart. Symptom Chart