The power steering control module (PSCM) receives a class 2 vehicle speed message from the engine control module (ECM) via the class 2 serial data circuit. The PSCM uses this vehicle speed message and other inputs to determine the desired amount of steering assist.
This diagnostic procedure supports the following DTC:
DTC C0000 Vehicle Speed Information Circuit
| • | The ignition is ON. | 
| • | DTC U1300, U1301, or U2100 are not set. | 
| • | Vehicle speed is greater than 8.1 km/h (5 mph). | 
The PSCM receives an invalid or no vehicle speed message from the ECM.
| • | DTC C0000 is stored in memory. | 
| • | The instrument panel cluster (IPC) message center displays the PWR STR warning message. | 
| • | Steering assist level defaults to 120 km/h (74.5 mph) vehicle speed level of assist. | 
| • | A current DTC will clear on the next consecutive malfunction-free ignition cycle. | 
| • | A history DTC will clear after 100 consecutive malfunction-free ignition cycles. | 
Step  | Action  | Yes  | No  | ||||||
|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Power Steering Schematics Connector End View Reference: Power Steering Connector End Views  | |||||||||
1  | Did you perform the Diagnostic System Check - Vehicle?  | Go to Step 2  | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information  | ||||||
 Does the scan tool indicate the presence of any engine control module (ECM) or transmission control module (TCM) DTCs?  | 
 
 
  | Go to Step 3  | |||||||
3  | 
 Does DTC C0000 reset?  | Go to Step 2  | System OK  | ||||||