Wheel Speed Sensor: Testing and Inspection

Tone wheels can cause erratic wheel speed sensor signals. Inspect tone wheels for the following possible causes.
- missing, chipped, or broken teeth
- contact with the wheel speed sensor
- wheel speed sensor to tone wheel alignment
- wheel speed sensor to tone wheel clearance
- excessive tone wheel runout tone wheel loose on its mounting surface
- incorrect model year tone wheel (driveshaft) installed

If a front tone wheel is found to need replacement, the drive shaft must be replaced. No attempt should be made to replace just the tone wheel.

If a rear tone wheel is found to need replacement, the rear hub and bearing must be replaced. No attempt should be made to replace just the tone wheel.

If wheel speed sensor to tone wheel contact is evident, determine the cause and correct it before replacing the wheel speed sensor or tone wheel.

Check the gap between the speed sensor head and the tone wheel to ensure it is within specifications.

Excessive wheel speed sensor runout can cause erratic wheel speed sensor signals. If tone wheel runout is excessive, determine if it is caused by a defect in the driveshaft assembly or hub and bearing. Replace as necessary.

Tone wheels are pressed onto their mounting surfaces and should not rotate independently from the mounting surface. Replacement of the front driveshaft or rear hub and bearing is necessary.

Pre-1998 models of this vehicle used a different antilock brake system which used a different tone wheel. Although the driveshafts may be interchangeable, the tone wheels are not. Do not use a pre-1998 driveshaft or rear hub and bearing on this model year vehicle, or vice-versa.