Some 2019-2022 Silverado 4500HD/5500HD/6500HD models may an illuminated ABS, traction control and/or brake warning MIL along with several DTCs set. These conditions may be due to an out-of-adjustment wheel speed sensor air gap, loose hub bearings, debris on the wheel speed sensor or a damaged reluctor ring. (Fig. 8)
Possible DTCs include:
- DTC C0500 or C0501 – Left Front Wheel Speed Sensor
- DTC C0506 or C0507 – Right Front Wheel Speed Sensor
- DTC C050C or C050D – Left Rear Wheel Speed Sensor
- DTC C0512 or C0513 – Right Rear Wheel Speed Sensor
Fig. 8
Before replacing the wheel speed sensor, perform the following inspections to help determine the root cause of the condition:
- Check that all tires are the same size and tread wear is even.
- Inspect the harness to the wheel speed sensor for any signs of damage or a loose terminal interface.
- Inspect the wheel speed sensor air gap. Make sure it is adjusted per the wheel speed sensor replacement document in the appropriate Service Information. A large gap may lead to an erratic signal while no gap may produce noise. If the wheel speed sensor air gap is out of adjustment, remove, clean, reinstall and then test the wheel speed sensor. During installation, ensure the wheel speed sensor bottoms out on the reluctor ring inside the hub. The air gap will be established by the contact between the reluctor ring and the wheel speed sensor.
- Clean any buildup of debris between the backing plate and the rotor, such as mud, ice, etc.
- Inspect for a loose wheel bearing and check the torque as specified in Service Information.
- Use an oscilloscope to look for any spikes in the wheel speed sensor pattern that may be caused by a damaged reluctor.
If no issues are found with any of these components, a new wheel speed sensor should be installed. Test drive the vehicle after any repairs to verify proper operation.
For more information, refer to #PIT5937.
– Thanks to Jim Will
