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C0455





DTC C0455

Diagnostic Instructions

- Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure Component Tests and General Diagnostics.
- Review Strategy Based Diagnosis for an overview of the diagnostic approach Component Tests and General Diagnostics.
- Diagnostic Procedure Instructions provides an overview of each diagnostic category Component Tests and General Diagnostics.

DTC Descriptor

DTC C0455 00: Front Steering Position Sensor Circuit

Diagnostic Fault Information






Circuit/System Description

The electronic brake control module (EBCM) supplies a 5 volt reference voltage to the yaw rate sensor/lateral acceleration sensor and the steering angle sensor. The steering angle sensor supplies input circuits to the electronic brake control module (EBCM) from the Digital Phase A, Phase B and 1 Analog signal circuit to determine the steering wheel angle. The analog signal is used to calibrate the steering angle sensor. The actual steering angle sensor position is determined by Phase A and Phase B signals which toggles between high and low when the steering wheel is turned. The two input signals Phase A and Phase B are approximately 90 degrees out of phase. Once calibrated, the EBCM dynamically interprets the relationship between the Phase A and Phase B inputs, which determines the rotation and the position of the steering wheel.

Conditions for Running the DTC

- The ignition is ON.
- Ignition voltage is greater than 9.5 volts.

Conditions for Setting the DTC

- Opens, short to ground, or voltage on the analog signal circuits.
- The EBCM detects an open on the steering wheel position signal A or signal B.
- The calculated steering angle from the steering angle sensor does not correlate with the steering angle calculated from the yaw rate.

Action Taken When the DTC Sets

- The EBCM disables the Vehicle Stability Enhancement System for the duration of the ignition cycle.
- A driver information center message and/or a warning message may be displayed.
- The Antilock Brake System (ABS) remains functional.

Conditions for Clearing the DTC

- The condition for the DTC is no longer present.
- The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

Diagnostic Aids

- The vehicle should not pull in either direction while driving straight on a level surface.
- Find out from the customer the conditions under which the DTC was set. This information will help to duplicate the concern.

Reference Information

Schematic Reference

Antilock Brake System Schematics Electrical Diagrams

Connector End View Reference

Component Connector End Views Diagrams

Description and Operation

ABS Description and Operation Description and Operation

Electrical Information Reference

- Circuit Testing Component Tests and General Diagnostics
- Connector Repairs Component Tests and General Diagnostics
- Testing for Intermittent Conditions and Poor Connections Component Tests and General Diagnostics
- Wiring Repairs Component Tests and General Diagnostics

Scan Tool Reference

Control Module References for EBCM Programming and Relearning

Circuit/System Verification

Observe the Steering Wheel Position parameter changes smoothly while turning the steering wheel through its entire range. Correlate zero reading with wheels in the straight ahead position. Drive the vehicle through a variety of maneuvers turning to the left, to the right and then straight ahead at a speed greater than 20 km/h (13 mph).

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the steering angle sensor.
2. Wait for 60 seconds, test for less than 5 ohms between the ground circuit terminal 8 and ground.
- If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition OFF, test for less than 5 ohms between the low reference circuit terminal 2 and ground.
- If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the EBCM.
4. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 7 and ground.
- If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.
5. Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal 1 and ground.
- If less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the EBCM.
- If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the EBCM.
6. Verify the scan tool Analog Steering Wheel Position Input parameter is less than 0.5 V.
- If greater than the specified range, test the signal circuit terminal 6 for a short to voltage. If the circuit tests normal, replace the EBCM.
7. Install a 3A fused jumper wire between the signal circuit terminal 6 and the 5 V reference circuit terminal 1. Verify the scan tool Analog Steering Wheel Position Input parameter is greater than 4.5 V.
- If less than the specified range, test the signal circuit terminal for a short to ground or an open/high resistance. If the circuit tests normal, replace the EBCM.
8. Verify the scan tool Digital SWPS Phase A parameter is High.
- If not the specified parameter, test the signal circuit terminal 3 for a short to ground. If the circuit tests normal, replace the EBCM.
9. Install a 3A fused jumper wire between the signal circuit terminal 3 and the low reference circuit terminal 2. Verify the scan tool Digital SWPS Phase A parameter is Low.
- If not the specified parameter, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the EBCM.
10. Verify the scan tool Digital SWPS Phase B parameter is High.
- If not the specified parameter, test the signal circuit terminal 4 for a short to ground. If the circuit tests normal, replace the EBCM.
11. Install a 3A fused jumper wire between the signal circuit terminal 4 and the low reference circuit terminal 2. Verify the scan tool Digital SWPS Phase B parameter is Low.
- If not the specified parameter, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the EBCM.
12. If all the circuits test normal, replace the steering angle sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

- Steering Wheel Position Sensor Centering Service and Repair
- Steering Wheel Position Sensor or Steering Shaft Lower Bearing Replacement Service and Repair
- Control Module References for EBCM replacement, setup, and programming Programming and Relearning
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