Diagnostic Aids
WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
- Any additional codes displayed with DTC C0550 should be diagnosed and repaired first.
- The rear wheel steering control module tests for multiple internal malfunctions and will store a DTC C0550 if one or more internal malfunctions are detected. Therefore, depending on which malfunction was detected, and what internal circuitry was affected, this DTC may cause various symptoms.
- Any condition resulting in the sensor supply voltage being pulled high or low could result in an erroneous DTC C0550.
- A fault in the battery positive voltage circuit from the 125A MEGA fuse can result in an erroneous DTC C0550.
DTC C0550
| Step | Action | Values | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Rear Wheel Steering Schematics Connector End View Reference: Rear Wheel Steering Connector End Views |
||||
| 1 | Did you perform the Diagnostic System Check-Rear Wheel Steering? | - | Go to Step 2 | Go to Diagnostic System Check - Rear Wheel Steering |
| 2 |
|
- | Go to Diagnostic Trouble Code (DTC) List | Go to Step 3 |
| 3 | With the scan tool, monitor the DTC information of the Rear Wheel Steering Control module. Does the information indicate that the DTC C0550 is current? |
- | Go to Step 4 | Go to Diagnostic Aids |
| 4 | With the scan tool, observe the sensor supply voltage in the rear wheel steering data. Is the voltage above the specified value? |
5.0 V | Go to Step 7 | Go to Step 5 |
| 5 | With the scan tool, observe the sensor supply voltage in the rear wheel steering data. Is the voltage below the specified value? |
0.25 V | Go to Step 8 | Go to Step 6 |
| 6 | Test for an open or short to ground in the battery voltage supply circuit of the 125 A MEGA fuse. Refer to Circuit Testing
and Wiring Repairs
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 11 | Go to Step 9 |
| 7 | Test the 5-volt reference circuit for a short to battery voltage. Refer to Circuit Testing
and Wiring Repairs
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 11 | Go to Step 9 |
| 8 | Test the 5-volt reference circuit for a short to ground. Refer to Circuit Testing
and Wiring Repairs
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 11 | Go to Step 9 |
| 9 | Inspect for poor connections at the rear wheel steering control module. Refer to Testing for Intermittent Conditions and Poor Connections
and Connector Repairs
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 11 | Go to Step 10 |
| 10 |
IMPORTANT:
Perform the learn alignment procedure. Refer to Measuring Wheel Alignment (w/Rear Wheel Steering)Measuring Wheel Alignment (w/o Rear Wheel Steering)
in Wheel Alignment. Replace the rear wheel steering control module. Refer to Rear Wheel Steering Control Module Replacement in Rear Wheel Steering.Did you complete the replacement? |
- | Go to Step 11 | - |
| 11 |
|
- | Go to Step 2 | System OK |