GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2008 🢒 STS 🢒 DTC 🢒 DTC C0475

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 provide overview of each diagnostic category.

DTC Descriptors

DTC C0475 00: Electric Steering Motor Circuit

DTC C0475 08: Electric Steering Motor Circuit Signal Invalid

Circuit/System Description

The power steering control module (PSCM) continuously monitors the voltage and current levels being commanded to the steering actuator.

Conditions for Running the DTC

Engine running.

Conditions for Setting the DTC
    • The lock solenoid voltage is greater then 3 volts with the lock off.
    • The lock solenoid voltage is less then 3 volts with the lock on.
    • The actuator drive line circuit is open.
    • The differences between actuator angle, and the real angle has changed.

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 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

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 Testing

DTC C0475 00

  1. Ignition OFF, disconnect the X2 harness connector at the PSCM.
  2. Test for less than 5 ohms between the ground circuit terminal 1 and ground.
    3. ⇒If greater than the specified range, test the ground circuit for an open/high resistance.
  3. Ignition ON, verify a test lamp illuminates between the B+ terminal 2 and ground.
    4. ⇒If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
  4. Ignition OFF, connect the X2 harness connector at the PSCM. Disconnect the X3 harness connector at the PSCM.
  5. Test for less than 5 ohms between the ground circuit terminal 3 and ground.
    6. ⇒If greater than the specified range, test the ground circuit for an open/high resistance.
  6. Ignition ON, verify a test lamp illuminates between the ignition circuit terminal 1 and ground.
    7. ⇒If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.
  7. With a scan tool, clear the DTC.
  8. Drive the vehicle under normal driving conditions. Verify DTC C0475 00 does not set.
    9. ⇒If the DTC sets, replace the PSCM.

DTC C0475 08

  1. Ignition OFF, disconnect the X2 harness connector at the PSCM.
  2. Test for less than 5 ohms between the ground circuit terminal 1 and ground.
    3. ⇒If greater than the specified range, test the ground circuit for an open/high resistance.
  3. Ignition ON, verify a test lamp illuminates between the B+ terminal 2 and ground.
    4. ⇒If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
  4. Ignition OFF, connect the X2 harness connector at the PSCM. Disconnect the X3 harness connector at the PSCM.
  5. Test for less than 5 ohms between the ground circuit terminal 3 and ground.
    6. ⇒If greater than the specified range, test the ground circuit for an open/high resistance.
  6. Ignition ON, verify a test lamp illuminates between the ignition circuit terminal 1 and ground.
    7. ⇒If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.
  7. Ignition OFF, connect the X3 harness connector at the PSCM. Disconnect the X1 harness connector at the PSCM.
  8. Test for less than 5 ohms between the signal circuit terminal 7 and the signal circuit terminal 8.
    9. ⇒If greater than the specified range, test both signal circuits for an open/high resistance. If the circuits test normal, replace the steering actuator.
  9. Test for less than 5 ohms between the signal circuit terminal 7 and the signal circuit terminal 14.
    10. ⇒If greater than the specified range, test both signal circuits for an open/high resistance. If the circuits test normal, replace the steering actuator.
  10. Test for less than 5 ohms between the signal circuit terminal 8 and the signal circuit terminal 14.
    11. ⇒If greater than the specified range, test both signal circuits for an open/high resistance. If the circuits test normal, replace the steering actuator.
  11. If all circuits test normal, replace the PSCM. Operate the vehicle within the Condition for Setting the DTC. Verify the DTC does not reset.
    12. ⇒If the DTC resets, replace the steering actuator.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Upper Intermediate Steering Shaft Replacement
    •  Control Module References for PSCM replacement, setup, and programming