C0161

DTC C0161

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.

* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC C0161 5A
- Antilock Brake System Brake Switch Not Plausible

DTC C0161 71
- Antilock Brake System Brake Switch Invalid Data

Circuit/System Description

When the brake pedal is applied, the Body Control Module sends a serial data message to the Electronic Brake Control Module in reference to the brake pedal positions. The Electronic Brake Control Module compares the correlation between the brake pedal position and the amount of brake pressure it senses from the brake pressure sensor, which is internal to the brake pressure modulator. It uses this information to control the vehicle during an stability control event.

Conditions for Running the DTC

* Ignition ON.

* Ignition voltage is greater than 8 V.

Conditions for Setting the DTC

* The Electronic Brake Control Module detects the brake pedal is not applied when the brake pressure is greater 15 bar (218 PSI) for 3 seconds.

* The Electronic Brake Control Module does not detect that the stop lamp switch signal changed after driving the vehicle at a speed greater than 40 km/h (25 MPH) and performing three brake stops.

Action Taken When the DTC Sets

* The Traction/stability Control Indicator Off turns ON, if equipped with electronic stability control.

* The Electronic Brake Control Module disables the Traction/stability for the duration of the ignition cycle, and the ABS remains functional.

Conditions for Clearing the DTC

* The condition for setting the DTC is no longer present.

* The history DTC will clear after 40 consecutive fault-free ignition cycles have occurred.

Diagnostic Aids

* DTC C0161 can set if the brake pedal is applied while accelerating.

* Diagnose all other stop lamp DTCs or Symptoms prior to performing this diagnostic procedure.

Reference Information

Schematic Reference

Antilock Brake System Schematics [1][2]Antilock Brakes / Traction Control Systems

Connector End View Reference

Component Connector End Views Fuel Pump and Level Sensor Assembly

Description and Operation

ABS Description and Operation Description and Operation

Electrical Information Reference

* Circuit Testing Circuit Testing

* Connector Repairs Connector Repairs

* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections

* Wiring Repairs Wiring Repairs

Scan Tool Reference

Control Module References Control Module References for scan tool information

Circuit/System Verification

1. Ignition ON.

2. Verify the stop lamps turn ON and OFF while applying and releasing the brake pedal.

• If the stop lamps do not turn ON and OFF
Refer to Symptoms - Lighting Symptoms - Lighting.

• If the stop lamps turn ON and OFF

3. Verify the Brake Pedal Position Sensor or the brake pedal are not binding causing residual brake pressure to be detected, while the brake lights operate properly.

• If a condition is found
Repair or replace the applicable component.

• If a condition is not found

4. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic repair.