Scan Tool Testing and Procedures

OPERATION SEQUENCE - Simulated by modes of Anti-lock Brake (ALB) checker.

NOTE: The wheel sensors and sensor wire harness are not checked by the ALB checker.





Mode 1 - Sends the simulated driving signal 0 mph (0 km/h) to 113mph (180 km/h) to 0 mph (0 km/h) of each wheel to the ABS control unit to check the system under normal driving. There should be no kickback.





Mode 2 - Sends the driving signal of each wheel, then sends the lock signal of the left-rear wheel to the ABS control unit to check the system under left rear wheel lock. There should be kickback.





Mode 3 - Sends the driving signal of each wheel, then sends the lock signal of the right-rear wheel to the ABS control unit to check the system under right-rear wheel lock. There should be kickback.





Mode 4 - Sends the driving signal of each wheel, then sends the lock signal of the left-front wheel to the ABS control unit to check the system under left-front wheel lock. There should be kickback.





Mode 5 - Sends the driving signal of each wheel, then sends the lock signal of the right-front wheel to the ABS control unit to check the system under right-front wheel lock. There should be kickback.

INSPECTION POINTS
If the ABS Indicator light comes on and the system stops during the inspection, confirm the ABS code and perform the appropriate troubleshooting for the code. Antilock Brake System

No Kickback In Modes 2 Through 5 - if ABS light does not come on, the following items are probable causes:
- Pressure switch stuck "ON."
- Clogged or stuck solenoid outlet valve.
- Modulator wire harness connectors improperly connected.