GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

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

DTC Descriptor

DTC C0545 00: Steering Wheel Torque Input Sensor

Circuit/System Description

The power steering control module (PSCM) continuously monitors the torque sensor input and output shaft sine wave frequency signals. As the steering wheel is turned and torsional twist is applied to the steering column shaft, the torque sensors input and output shaft sine wave frequency signals are processed by the PSCM to detect and calculate the steering torque.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

The PSCM detects open, short to ground or short between any of the torque sensor circuits.

Actions Taken When DTC Sets

    • DTC C0545 is stored in memory.
    • The driver information center (DIC) displays the SERVICE POWER STEERING warning message.
    • No steering assist.

Conditions for Clearing the DTC

    • A current DTC will clear on the next malfunction free ignition cycle.
    • A history DTC will clear after 100 consecutive malfunction free ignition cycles.

Reference Information

Schematic Reference

Power Steering Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Power Steering System Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector X3 at the PSCM.
  2. Ignition OFF, test for 2-20 Ω between the signal circuit terminal 4 and the signal circuit terminal 2.
  3. If not within the specified range, test the signal circuits for a short to ground or an open/high resistance. If circuits test normal, replace the steering column.
  4. Ignition OFF, test for 100-500 Ω between the signal circuit terminal 8 and the signal circuit terminal 1.
  5. If not within the specified range, test the signal circuits for a short to ground or an open/high resistance. If circuits test normal, replace the steering column.
  6. Ignition OFF, test for 300-1000 Ω between the signal circuit terminal 7 and the signal circuit terminal 1.
  7. If not within the specified range, test the signal circuits for a short to ground or an open/high resistance. If circuits test normal, replace the steering column.
  8. Ignition OFF, test for 50-200 Ω between the signal circuit terminal 6 and the signal circuit terminal 1.
  9. If not within the specified range, test the signal circuits for a short to ground or an open/high resistance. If circuits test normal, replace the steering column.
  10. Ignition OFF, test for 200-800 Ω between the signal circuit terminal 5 and the signal circuit terminal 1.
  11. If not within the specified range, test the signal circuits for a short to ground or an open/high resistance. If circuits test normal, replace the steering column.
  12. Ignition OFF, test for greater than 1.0 MΩ between the signal circuit terminal 2 and the signal circuit terminal 1.
  13. If less than the specified range, test the signal circuits for a short to ground or an open/high resistance. If circuits test normal, replace the steering column.
  14. Ignition OFF, test for greater than 1.0 MΩ of resistance between the signal circuit terminal 1 and ground.
  15. If less than the specified range, test the signal circuit for a short to ground. If circuits test normal, replace the steering column.
  16. Ignition OFF, test for greater than 1.0 MΩ between the signal circuit terminal 2 and ground.
  17. If less than the specified range, test the signal circuit for a short to ground. If circuits test normal, replace the steering column.
  18. If all circuits test normal, replace the PSCM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Steering Column Replacement
    •  Control Module References for PSCM replacement, setup, and programming