C127D

DTC C0161 or C127D

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 00
- Antilock Brake System (ABS) Brake Switch Circuit

DTC C127D
- Antilock Brake System (ABS) Brake Switch Circuit

DTC C0161 04
- Antilock Brake System (ABS) Brake Switch Circuit Open Circuit

DTC C0161 0E
- Antilock Brake System (ABS) Brake Switch Circuit Resistance Below Threshold

Circuit/System Description

The electronic brake control module detects inputs from the brake pressure sensor, vehicle speed, and a serial data message from the body control module that the brake pedal is applied. When the vehicle is stopping the monitors for the brake pedal is pressed, with the brake pressure increasing and the vehicle is slowing down, or when the vehicle is accelerating, the brake pedal is not pressed and brake pressure is not increasing.

Conditions for Running the DTC

C0161 00, C0161 04 or C127D

* The ignition is ON.

* The ignition voltage is greater than 10 volts.

* The brake pedal is applied.

C0161 0E

* Ignition ON.

* The vehicle speed is greater than 15 km/h (9 MPH).

* The ignition voltage is greater than 10 volts.

* The accelerator pedal position is greater than 20 percent.

Conditions for Setting the DTC

C0161 04

The brake pedal switch is sensed as not applied while the pressure sensor and travel sensor indicate the brake pedal is applied.

C0161 00, C0161 0E or C127D

The brake pedal is sensed as applied while the vehicle speed is greater than 15 km/h (9 MPH).

Action Taken When the DTC Sets

The ABS, the traction control and the vehicle stability enhancement system remains functional.

Conditions for Clearing the DTC

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

* The electronic brake control module clears the history DTC when a current DTC is not detected in 40 consecutive drive cycles.

Diagnostic Aids

* Engine braking.

* This DTC may set during off road driving in sand or hilly terrain.

* DTC C0161 5A can set if the brake is applied while accelerating.

* The electric trailer brake is applied without the brake pedal being applied.

* Anything that may cause the vehicle to decelerate without the brake pedal being applied.

* Inform the customer that this DTC will set if the brake is applied for 60 seconds while at speeds greater than 21 km/h (13 MPH), such as a two footed driving.

Reference Information

Schematic Reference

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

Connector End View Reference

Component Connector End Views Connector End Views By Name

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 pressing 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. Refer to Diagnostic Aids.