C0161

Antilock Brake System

Diagnostic Information and Procedures

DTC C0161

Circuit Description

The brake switch informs the EBCM when the brake is depressed. The brake switch is normally closed, supplying 12 volts to the EBCM when the brake is released. When the brake pedal is pressed, voltage on the TCC brake switch signal circuit is 0 volts.

Conditions for Running the DTC

Any of the following conditions may cause the DTC to run.
- The vehicle accelerates from 0 km/h (0 mph) to a speed greater than 56 km/h (35 mph).
- The vehicle experiences an ABS event involving all hydraulic circuits.
- The EBCM detects that the master cylinder pressure is greater than 1400 kPa (200 PSI) and that the vehicle is decelerating.

Conditions for Setting the DTC

Any of the following conditions may cause the DTC to set.
- Voltage on the TCC brake switch signal circuit is always low.
- Voltage on the TCC brake switch signal circuit is always high.
- Voltage on the TCC brake switch signal circuit is high for 0.5 - 4.0 seconds when voltage is expected to be low.

Action Taken When the DTC Sets

- The EBCM disables the VSES.
- The TCS operates with engine torque reduction capability only.
- The message center displays the service stability system message.

Conditions for Clearing the DTC

The Conditions for Setting the DTC are no longer present and you use the scan tool Clear DTC's function.

Diagnostic Aids

Thoroughly inspect connections or circuitry that may cause an intermittent malfunction. Refer to Testing for Intermittent and Poor Connections, Connector Repairs, Testing for Electrical Intermittents and to Wiring Repairs in Wiring Systems.

Test Description

The numbers below refer to the step numbers on the diagnostic table.
4. This step tests for a shorted stop lamp switch.
5. This step tests for an open stop lamp switch.

DTC C0161 Steps 1 - 4:

DTC C0161 Steps 5 - 12: