Chevrolet Trax: DTC C0161: Antilock brake system brake switch

Diagnostic Instructions

• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• 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 may 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(Encore), Antilock Brake System Schematics (Trax)

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - (Trax)

Description and Operation

ABS Description and Operation

Electrical Information Reference

• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs

Scan Tool Reference

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 .

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 appropriate component.

If a condition is not found

4. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

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