Antilock Brake System - Non-Hybrid Greater than/Equal to 3900 kg (8600 lb) GVW

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 Descriptor

DTC C0161 5A

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ABS Brake Switch Circuit Plausibility Failure

Circuit/System Description

The electronic brake control module (EBCM) detects inputs from the brake pressure sensor, vehicle speed, and a serial data message from the body control module (BCM) that the brake pedal is applied. When the vehicle is stopping the EBCM 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

* Ignition ON.

* The vehicle speed is greater than 16 km/h (10 mph).

Conditions for Setting the DTC

* The EBCM detects the vehicle speed greater than 21 km/h (13 mph), the brake pedal is applied for one minute, and brake pressure is not increasing.

* The EBCM detects brake pedal is released and the vehicle speed is decreasing while the brake pressure is increasing.

Action Taken When the DTC Sets

* A driver information center message and/or a warning indicator may be displayed.

* The EBCM disables the antilock brake system, the traction control and the vehicle stability enhancement system for the duration of the ignition cycle.

Conditions for Clearing the DTC

* The condition for the DTC is no longer present.

* The EBCM clears the history DTC when a current DTC is not detected in 40 consecutive drive cycles.

Diagnostic Aids

* Engine braking.

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

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

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

* The electric trailer brake is applied 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 1-2 Shift Solenoid (SS) Valve (M30)

Description and Operation

ABS Description and Operation (Without JL4) Description and OperationABS Description and Operation (With JL4) 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

Note:
If the ABS, and/or Traction Control indicators are ON with DTC C0161 5A set in history, perform the conditions for clearing the DTC and inform the customer that two footed driving may set this DTC.

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.