Diagnostic Aids
WARNING: This page is about a different car, the 2003 GMC Sierra, 2003 GMC Cab & Chassis Sierra, 2003 Chevrolet Silverado, and 2003 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
- Most of the occurrences of this DTC are caused by a short or an open vehicle speed sensor signal circuit to the rear wheel steering control module. Review rear wheel steering system operation or, with the customer, verify the condition under which the DTC set.
- Inspect for poor connections at the harness connector of the rear wheel steering control module. Refer to TESTING FOR INTERMITTENT AND POOR CONNECTIONS and to CONNECTOR REPAIRS .
- Observe the rear wheel steering mode select switch. If all of the mode indicator LEDs are illuminated the rear wheel steering control module has lost its memory settings and the scan tool must be used to re-calibrate the rear wheel steering alignment data in the rear wheel steering control module. Refer to MEASURING WHEEL ALIGNMENT (WITH REAR WHEEL STEERING) or MEASURING WHEEL ALIGNMENT (WITHOUT REAR WHEEL STEERING) .