Diagnostic Instructions
DTC Descriptor
DTC C0161: TCS Brake Switch Circuit
Circuit/System Description
The brake pedal position (BPP) sensor is an input to the body control module (BCM). The BCM activates the brake lamps when the BPP is in an applied state. The BCM then sends a brake pedal applied state status via high speed GMLAN serial data
messages to the electronic brake control module (EBCM) and other electronic control modules. The BPP sensor is a potentiometer type sensor with a 5 volt reference circuit and a low reference circuit. The BCM supplies the 5 volt reference
to the BPP.
Conditions for Running the DTC
The Ignition is ON.
Conditions for Setting the DTC
| • | Brake pedal is sensed as applied during moderate to high vehicle acceleration. |
| • | Brake pedal state is observed as applied for 144 consecutive seconds. |
Action Taken When the DTC Sets
| • | EBCM disables the traction control system (TCS) for the duration of the ignition cycle. |
| • | The vehicle dynamics caution (VDC) indicator turns ON |
| • | The driver information center (DIC) displays the SERVICE TRACTION CONTROL message |
Conditions for Clearing the MIL/DTC
| • | The ABS indicator may remain illuminated after repairs are made and DTCs are cleared, until the vehicle is operated at speeds greater than 13 km/h (8 mph) and the self test is completed. |
| • | The condition for setting the DTC is no longer present. |
| • | The EBCM will clear a history DTC when a malfunction is not detected in 100 consecutive drive cycles. |
Diagnostic Aids
The DTC C0161 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
Antilock Brake System Connector End Views
Electrical Information Reference
Scan Tool Reference
Scan Tool Data List
Circuit/System Testing
- With the scan tool, check the vehicle for brake pedal position (BPP) related DTCs.
| ⇒ | If DTC C0277 or C0297 are present, diagnose BPP DTCs. |
- Lightly apply and release the brake pedal. The stop lamps should illuminate and then turn OFF.
- If no Lighting System problems can be found, refer to Diagnostic Aids.
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
Control Module References
for BCM and EBCM replacement, setup, and programming
