GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2009 🢒 STS 🢒 Driver Information and Entertainment 🢒 Cellular, Entertainment, and Navigation 🢒 DTC C0176

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 C0176 54: System Thermal Error Temperature High

Circuit/System Description

The power steering control module (PSCM) uses a combination of commanded motor voltage and current levels to calculate an estimated power steering system temperature. If the PSCM detects a high system temperature event is occurring, it will disable the active steering.

Condition for Running the DTC

Engine Running.

Conditions for Setting the DTC

The PSCM detects a high system temperature.

Action Taken When the DTC Sets
    • Active Steering is disabled.
    • SERVICE STEERING SYS and/or STABILITY SECURE MODE is displayed on the DIC.

Conditions for Clearing the DTC
    • A current DTC will clear when the power steering system temperature returns to normal.
    • A history DTC will clear after 100 consecutive malfunction-free ignition cycles.

Diagnostic Aids
    • DTC C0176 54 does not indicate that a malfunction has occurred. Rather that the PSCM had to limit current to the power steering motor to avoid thermal damage to the power steering system components. DTC C0176 54 is set in history does not indicate that a malfunction has occurred, the system has reached operation limits, and has returned to normal operation.
    • Ensure that no mechanical steering components such as the power steering gear assembly, universal joints, ball joints or tie rod ends are mechanically binding.

Reference Information

Schematic Reference

Power Steering Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Active Front Steering 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 Verification

Important: Allow the Active Front Steering system to cool down before performing this test.

  1. Ignition ON, verify the scan tool AFS Heat Protection parameter is Inactive.
    2. ⇒If not the specified value, replace the PSCM.
  2. With a scan tool, clear the DTC.
  3. Drive the vehicle under normal driving conditions. Verify DTC C0176 does not set.
    4. ⇒If the DTC sets, replace the PSCM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for PSCM replacement, setup, and programming