DTC 21 - Faulty Wheel Speed Sensor Output
NOTE:
If after all testing procedures have been completed system is not functioning properly, substitute ECU with known-good unit and retest.
- DTC will set if ECU detects wheel speed sensor has no output signal. DTC will also set if wheel sensor voltage output is low while driving vehicle.
- Inspect all wheel speed sensor rotors for damaged and missing teeth. Replace any damaged rotors. Using an oscilloscope, check waveform patterns. See Figure . If all rotors are okay, go to next step.
- Test wheel speed sensor. See WHEEL SPEED SENSOR TESTING . Replace wheel sensor as necessary. Ensure wheel speed sensor-to-rotor gap is within specification. See WHEEL SPEED SENSOR under ADJUSTMENTS.