Possible Causes
- Wheel speed sensor input concern
- Wheel speed sensor
- AL1: CHECK FOR OTHER ABS MODULE DTCS
- Review the recorded results from the ABS module self-test.
- Are any wheel speed sensor DTCs present which are NOT shown in the ABS DTC Fault Trigger Conditions table?
Yes No DIAGNOSE those DTCs first. REFER to the ABS Module DTC Chart . INSTALL a new wheel speed sensor for the one in question. REFER to the appropriate Removal and Installation procedure in Anti-Lock Brake System (ABS) and Stability Control article