Diagnostic Instructions
DTC Descriptor
DTC C0161: Antilock Brake System (ABS)/Traction Control System (TCS) Brake Sensor 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 serial data message 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
Engine Running and the vehicle is moving.
Conditions for Setting the DTC
| • | EBCM detects the brake pedal is applied from the brake pressure sensor reading, and the BPP signal is not detected for 5 seconds when the vehicle is stopping, or when the brake pressure sensor reading indicates the brake pedal is not applied
and BPP signal is detected for 144 seconds when driving. |
| • | No brake pressure faults are detected. |
Action Taken When the DTC Sets
| • | EBCM disables the traction control system (TCS) and stability control for the duration of the ignition cycle. |
| • | The traction control warning indicator and the stability control warning indicator turns ON. |
Conditions for Clearing the DTC
| • | The warning indicators may remain illuminated after repairs are made until the DTCs are cleared, and the vehicle is operated at speeds greater than 13 km/h (8 mph) for the self test to complete. |
| • | 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 when driving.
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
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Ignition ON, observe the EBCM scan tool BPP Signal parameter. The reading should be Released when the pedal is not pressed, and Applied when pressed.
- Verify DTC C0277 or C0278 is not set.
- Replace the EBCM.
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for EBCM replacement, setup, and programming
