C0455

DTC C0455

Circuit Description

The electronic brake control module (EBCM) receives several inputs from the steering wheel position sensor. Three digital square wave signal inputs are wired directly to the EBCM harness connector, however, only signals A and B are used or monitored. The failure of the index pulse signal does not effect vehicle stability enhancement system (VSES) function. The EBCM also receives an analog steering wheel position input on the steering wheel position sensor signal 1 circuit. Ignition voltage is supplied to the digital portion of the steering wheel position sensor. The analog portion of the steering wheel position sensor is supplied a 5-volt reference from the EBCM.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC C0455 Front Steering Position Sensor Circuit

Conditions for Running the DTC

^ The ignition is ON.
^ The VSES sensors have been successfully initialized. Refer to ABS Description and Operation (W/JL4) ABS Description and Operation (W/O JL4) for a complete explanation of VSES sensor initialization.

Conditions for Setting the DTC

Any of the following conditions may cause the DTC to set:

^ The analog steering wheel position signal does not correlate with the digital steering wheel position signals.
^ When driven forward in a straight line, the centered steering angle differs by more than 30 degrees from the centered steering angle when the sensors are initialized.
^ The EBCM detects an erratic signal from steering wheel position signal A or signal B.
^ The EBCM detects an open or shorted steering wheel position analog signal.
^ The EBCM detects an erratic steering wheel position analog signal.
^ The EBCM detects an open or shorted steering wheel position signal A or signal B, after having received a valid signal during the same ignition.

Action Taken When the DTC Sets

^ The EBCM disables the VSES.
^ The stability system caution indicator is illuminated.

Conditions for Clearing the DTC

The condition for setting the DTC is no longer present and you use the scan tool Clear DTCs function.

Diagnostic Aids

^ DTC C0455 may be falsely set if you did not turn OFF the ignition for 5 seconds after clearing DTCs from the EBCM. This is why all diagnostic tables which apply to this system always instruct you to turn OFF the ignition for 5 seconds after clearing DTCs. If this DTC has set after you cleared DTCs from the EBCM or used the scan tool to clear all DTCs from all modules and you did not cycle the ignition afterward, it is likely that no actual malfunction exists.
^ Whenever any one of the steering signals to the EBCM is lost, the scan tool displays a fixed steering wheel position, which indicates the last known steering wheel position. This can aid you in diagnosing an intermittent malfunction.
^ If the DTC does not reset during step 2 or 3 of the diagnostic procedure, the stability system not ready indicator may be displayed due to an unsuccessful initialization. This occurs if the EBCM does not receive any signal from one or both of the digital inputs during the entire ignition cycle. If this occurs, refer to Stability System Not Ready Indicator Always On for further diagnosis.
^ Inspect the vehicle for proper wheel alignment. Ensure the vehicle does not pull toward the left or right while driving straight forward on a level surface.
^ Communicate with the customer to determine the conditions under which the instrument panel cluster (IPC) illuminates the stability system caution indicator. Learning the conditions under which the DTC sets may help you duplicate the failure.
^ Use the Snapshot function on the scan tool in order to assist you in locating an intermittent malfunction.

Test Description

The number below refers to the step number on the diagnostic table.
2. If the DTC sets without turning the steering wheel or driving the vehicle, a malfunction exists in the analog steering wheel position signal to the EBCM.

Step 1 - Step 7:

Step 8 - Step 15:

Step 16 - Step 19: