Circuit Description
The electronic brake control module (EBCM) calibrates the steering sensor output so that the output reads zero when the steering wheel is centered. Using the yaw rate input, lateral accelerometer input, and the wheel speed sensor inputs, the initial steering center position is calculated after driving greater than 10 km/h (6 mph) for more than 10 seconds in a straight line on a level surface.
DTC Descriptors
This diagnostic procedure supports the following DTCs:
| • | DTC C0253 Centering Error |
| • | DTC C0254 Steering Sensor and/or Lateral Accelerometer Bias |
Conditions for Running the DTC
C0253
| • | The ignition is ON. |
| • | Ignition voltage is greater than 8 volts. |
C0254
| • | The ignition is ON. |
| • | Ignition voltage is greater than 8 volts. |
| • | The steer angle has been centered. |
Conditions for Setting the DTC
C0253
The vehicle speed is greater than 40 km/h (25 mph) for 10 minutes without completing steer angle centering.
C0254
The steering sensor bias moves greater than 40 degrees after steer centering was accomplished.
Action Taken When the DTC Sets
| • | The EBCM disables the vehicle stability enhancement system (VSES) for the duration of the ignition cycle. |
| • | The driver information center (DIC) displays the Service Stability System message. |
| • | The ABS remains functional. |
Conditions for Clearing the DTC
| • | The condition for the DTC is no longer present and the DTC is cleared with a scan tool. |
| • | The electronic brake control module (EBCM) automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles. |
Diagnostic Aids
| • | Check the vehicle for proper alignment. The car should not pull in either direction while driving straight on a level surface. |
| • | The Snapshot function on the scan tool can help find an intermittent DTC. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
Perform the Steering Position Sensor Test in order to verify that the steering wheel position sensor (SWPS) is operating properly.
-
Verify that the lateral accelerometer input parameter is within the valid range.
-
Verify that the yaw rate input parameter is within the valid range.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Antilock Brake System Schematics | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |
Did the SWPS pass the test? | -- | Go to Step 3 | Go to Step 7 | |
With a scan tool, observe the Lateral Accelerometer Input parameter in the vehicle stability enhancement system (VSES) data list. Does the scan tool display within the specified range? | 2.3-2.7 V | Go to Step 4 | Go to Step 8 | |
With a scan tool, observe the Yaw Rate Sensor Input parameter in the VSES data list. Does the scan tool display within the specified range? | 2.3-2.7 V | Go to Step 5 | Go to Step 8 | |
5 |
Does the DTC reset? | -- | Go to Step 6 | Go to Diagnostic Aids |
6 | Replace the electronic brake control module (EBCM). Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 9 | -- |
7 | Replace the steering wheel position sensor (SWPS). Refer to Steering Wheel Position Sensor or Steering Shaft Lower Bearing Replacement . Did you complete the replacement? | -- | Go to Step 9 | -- |
8 | Replace the yaw rate/lateral accelerometer sensor. Refer to Vehicle Yaw Sensor with Vehicle Lateral Accelerometer Replacement . Did you complete the replacement? | -- | Go to Step 9 | -- |
9 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
