Circuit Description
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2003 GMC Yukon XL, 2003 GMC Yukon, 2003 Chevrolet Tahoe, 2003 Chevrolet Suburban, and 2003 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
When the ignition switch is turned ON, the rear wheel steering control module monitors communications between its internal microprocessors and performs self-diagnostic tests. If an internal malfunction is detected, the rear wheel steering control module will store a DTC C0550 in its memory.