Diagnostic Aids

Be sure that the speed sensor wiring is properly routed and retained. This will help to prevent false signals due to the pickup of electrical noise.

It is very important to perform a thorough inspection of the wiring and the connectors. Failure to inspect the wiring and the connectors carefully and completely may result in misdiagnosis, causing part replacement with the reappearance of the malfunction.

IMPORTANT: If the WSS signal fault input to the electronic brake control module (EBCM), the ABS warning lamp turns ON. If a sensor signal fault can be removed by the scan tool, the ABS warning lamp doesn't turn OFF. In order to turn ABS warning lamp OFF, you should drive the vehicle up to 12 km/h.

You can use the scan tool to monitor wheel speeds during a road test. Watch the wheel speeds being displayed on the scan tool to see if any of the readings are unusual, such as 1 sensor varying in speed from the other 3, a signal going intermittently high or low, etc. If this does not identify the intermittent, wet the speed sensor harness on the underside of the vehicle and perform a road test, monitoring the wheel speeds with the scan tool.