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 Descriptors

DTC C0163: Antilock Brake System (ABS)/Traction Control System (TCS) Brake Switch/Sensor Circuit Low

DTC C0164: Antilock Brake System (ABS)/Traction Control System (TCS) Brake Switch/Sensor Circuit High

DTC C0165: Antilock Brake System (ABS)/Traction Control System (TCS) Brake Switch/Sensor Circuit Open

Circuit Description

The body control module (BCM) receives a signal from the brake pedal position (BPP) sensor. The BCM illuminates the stop lamps by applying B+ to the stop lamp supply voltage circuit. The electronic brake control module (EBCM) receives a voltage input from the stop lamp supply voltage circuit to determine if the brake pedal is applied.

Conditions for Running the DTCs

C0163, C0164 or C0165

Ignition ON.

Conditions for Setting the DTC

C0163

The DTC sets when the EBCM detects that the vehicle decelerates without a brake apply signal. All of the conditions below must be met 2 times before the DTC sets:

    • The EBCM does not receive a voltage input from the stop lamp supply voltage circuit.
    • ABS, vehicle stability enhancement system (VSES), and traction control system (TCS) is not active.
    • Vehicle speed exceeds 24 km/h (15 mph) and decelerates greater than 12 km/h (7 mph) per second.
    • Vehicle speed drops below 24 km/h (15 mph) during deceleration.

C0164

The DTC sets when the EBCM detects that the vehicle accelerates with a brake apply signal. All of the conditions below must be met 2 times before the DTC sets:

    • The EBCM receives a voltage input from the stop lamp supply voltage circuit.
    • Vehicle speed exceeds 40 km/h (25 mph).
    • Vehicle acceleration exceeds 8 km/h (5 mph) per second.

C0165

The DTC sets when the EBCM detects an open in the stop lamp supply voltage circuit. The EBCM determines an open circuit if the voltage at the stop lamp supply voltage circuit is between 75 percent and 40 percent of ignition voltage.

Action Taken When the DTC Sets

If equipped, the following actions occur:

    • The EBCM disables the antilock brake system (ABS)/traction control system (TCS)/vehicle stability enhancement system (VSES) for the duration of the ignition cycle.
    • The ABS indicator illuminates
    • The Red brake indicator illuminates.
    • The Stability Control indicator illuminates.
    • The driver information center (DIC) displays Service Stability control and Service Traction System message.

Conditions for Clearing the DTC

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

Diagnostic Aids

The DTC C0164 can be set if the vehicle has been driven with the brake applied during acceleration.

Reference Information

Schematic Reference

Antilock Brake System Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

ABS 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. Verify that DTC P0573, C0277, C0278, or C0283 is not set.
  2. If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle
  3. Ignition ON, observe the operation of the stop lamps and the center high mounted stop lamp (CHMSL) while pressing and depressing the brake pedal. The stop lamps and the CHMSL should go ON and OFF.
  4. If the stop lamps or the CHMSL is always OFF refer to Stop Lamps Malfunction.
  5. Verify the calibration of the brake pedal position sensor, refer to Brake Pedal Position Sensor Calibration.
  6. Verify DTC C0163-C0165 is not set.
  7. If DTC is set, replace the BPMV and verify DTC does not reset. If DTC resets, replace the EBCM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Brake Pedal Position Sensor Calibration
    •  Control Module References for EBCM replacement, setup, and programming