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C0455




DTC C0455

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.

DTC Descriptor
DTC C0455 00
- Front Steering Position Sensor Circuit

Diagnostic Fault Information





Circuit/System Description

The steering angle sensor supplies input circuits to the electronic brake control module (EBCM) from the Phase A and Phase B, the Index Pulse Phase C circuits, and 1 Analog signal circuit for steering wheel angle. The analog signal is used along with the index pulse to calibrate the steering angle sensor. The steering angle position is then determined by Phase A and Phase B signals. The 2 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, and determines the position of the steering wheel and the direction of the steering wheel rotation.

Conditions for Running the DTC

* The ignition is ON.
* Ignition voltage is greater than 9.5 V.

Conditions for Setting the DTC

* Opens, short to ground, or voltage on the analog signal circuits.
* 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 (VSES) for the duration of the ignition cycle.
* The driver information center (DIC) displays the Service Stability System message.
* The Antilock Brake System (ABS) remains functional.
* The VSES Caution indicator turns ON.

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

* During diagnosis, park the vehicle on a level surface.
* 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 failure.
* Verify the steering wheel angle sensor is installed correctly.
* Verify the steering wheel is properly installed with the alignment arrow on the steering wheel aligned to the mark on the steering shaft.
* The snapshot function on the scan tool can help find an intermittent DTC.

Reference Information
Schematic Reference

Antilock Brake System Schematics (Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector End Views By Name)
Description and Operation

ABS Description and Operation (ABS (Non-Hybrid Less than 3900 kg (8600 lb) GVW))
Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

Scan Tool Reference

Control Module References (Control Module References) for scan tool information.

Circuit/System Verification

With scan tool installed, clear the DTCs. Turn the steering wheel through its full range and back to straight ahead to center the steering angle sensor. Using a scan tool, observe the Steering Wheel Position parameter changes smoothly while turning steering wheel through the entire range. Correlate zero reading with wheels in the straight ahead position. Drive the vehicle through a variety of maneuvers turning to the left, right and then straight ahead at a speed greater than 20 km/h (13 mph).

If the DTC did not set as a current DTC see diagnostic aids.

Circuit/System Testing

1. Verify that DTC C1100, or C0710 is not set.

If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code (DTC) List - Vehicle).

2. Ignition OFF, disconnect the harness connector at the steering angle sensor.
3. Test for less than 20 ohm 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, 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.

5. Test for 4.8 - 5.2 V between the 5 V reference circuit terminal 1 and the signal circuit terminal 6.

If not within the specified range, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the EBCM.

6. Ignition OFF, disconnect the harness connector at the EBCM.
7. Test for infinite resistance between the signal circuit terminal 4 and ground.

If less than the specified range, test the signal circuit for a short to ground.

8. Connect the harness connector at the EBCM.

Note: When measuring voltage, the voltage values are based on a battery charge of 12.5 V and the steering wheel is in the center position.

9. Ignition ON, at the steering angle sensor connector harness, test for 6.8 - 11 V between the signal circuit terminals listed below and ground.

* Phase A terminal 3
* Phase B terminal 4
* Phase C terminal 5

If less than the specified range, test the appropriate signal 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 appropriate signal circuit for a short to voltage. If the circuit tests normal, replace the EBCM.

10. If the circuits test normal, replace the steering angle sensor.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Steering Wheel Position Sensor Replacement (Steering Wheel Position Sensor Replacement)
* Control Module References (Control Module References) for EBCM replacement, programming and setup