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.
- Inspect for poor connections at the harness connector of the rear wheel steering control module, rear wheel position sensor and the rear wheel steering motor connectors. Refer to TESTING FOR INTERMITTENT AND POOR CONNECTIONS and to CONNECTOR REPAIRS .
- Inspect the rear wheel position sensor for damage. If none is found then remove and inspect the sensor and coupler for damage or water intrusion. Refer to Rear Position Sensor Replacement . If water damage is found, refer to Rack and Pinion Boot Replacement .
- 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) .