Inspection And Road Test

1. Visually inspect the Anti-Lock Brake (ABS) system for damaged or disconnected components and connectors.
2. Verify the brake lamps are operational. If they are not, repair them prior to continuing.
3. Connect a scan tool to the Data Link Connector (DLC) located under the instrument panel to the left of the steering column. If the scan tool does not power-up, check the power and ground supplies to the connector.
4. Turn the ignition key to the ON position.
5. Using the scan tool, read and record any Diagnostic Trouble Codes (DTCs). If any DTCs are present, refer to the appropriate diagnostic information.

   If no problems are observed, it will be necessary to road test the vehicle.

   Many ABS conditions judged to be a problem by the driver may be normal operating conditions. To become familiarized with the normal operating characteristics of the anti-lock braking system. Refer to DESCRIPTION AND OPERATION .

   WARNING:

   Conditions that result in turning on the red brake warning indicator lamp may indicate reduced braking ability.

   Before road testing a brake complaint vehicle, note whether the red BRAKE warning indicator lamp, amber ABS warning indicator lamp or both are illuminated. If the red BRAKE warning indicator is illuminated there is a brake hydraulic malfunction that must be corrected before driving the vehicle

   Refer to BASE BRAKE SYSTEM .

   The following conditions will cause the red BRAKE lamp to illuminate:

   • Low fluid in the brake reservoir
   • Parking brake engaged
   • Brake hydraulic system problem
   • ABS issue that will not allow the brake proportioning function

   If the amber ABS warning indicator is illuminated, road test the vehicle as described below. If the amber ABS warning indicator is illuminated the ABS is not functional. The ability to stop the vehicle using the base brake system should not be affected.

6. Turn the key to the OFF position and then back to the ON position. Note whether the amber ABS warning indicator lamp stays illuminated.
7. If the amber ABS warning indicator lamp stays illuminated, drive the vehicle approximately 25 km/h (15 mph) to complete the ABS start-up and drive-off cycles. If the amber ABS warning indicator lamp stays illuminated, refer to the appropriate diagnostic information.
8. If the amber ABS warning indicator lamp goes off at any time, drive the vehicle a short distance. Accelerate the vehicle to a speed of at least 50 km/h (31 mph). Bring the vehicle to a complete stop, braking hard enough to cause the ABS to cycle. Repeat this action several times. Using the scan tool, read and record any (DTCs). If any DTCs are present, refer to the appropriate diagnostic information.

Electronic Stability Control System (ESC) 

Perform a road test in a open area that allows vehicle to be driven in circles without and obstruction or danger to traffic.

Drive vehicle in curved path for 2-3 seconds until the Electronic Stability Program (ESP) system is activated and the ESP warning light illuminates.