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 Descriptor

DTC C0161 00

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ABS Brake Switch Circuit

Circuit/System Description

The electronic brake control module (EBCM) monitors the brake pressure sensor voltage, vehicle speed, and a serial data message from the body control module (BCM) that the brake pedal is either Applied or Released. When the vehicle is stopping the EBCM detects the brake pressure sensor voltage increases and correlates the readings to the serial data message from the BCM that the brake pedal is applied, and the vehicle is slowing down, or when the vehicle is accelerating, the brake pedal is Released and brake pressure sensor voltage returns to 0 volts.

Conditions for Running the DTC

* The ignition is ON.

* The vehicle speed is greater than 11 km/h (7 mph).

Conditions for Setting the DTC

* The EBCM detects the vehicle speed is greater than 11 km/h (7 mph), the brake pedal is applied for one minute, and the brake pressure detects pressure less than the set value.

* The EBCM detects the vehicle speed decreases, the brake pedal is released and the brake pressure sensor detects an increase in pressure.

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 setting the DTC is no longer present.

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

Note:
During normal diagnostic and/or repair verification technicians may find that the ABS, and/or Traction Control indicators may be ON with NO DTCs displayed by the EBCM. Do not replace the EBCM for this condition.

If the ABS, and/or Traction Control are ON with no DTCs set, perform the following steps:

1. Remove the key from the ignition, open and close the driver's door to turn off retained accessory power (RAP), and wait 60 seconds.

2. Ignition ON, if the ABS, and/or Traction Control telltales are still illuminated, operate the vehicle at speeds greater than 15 km/h (10 mph) to complete the self test. The EBCM should request all telltale indicators to turn OFF.

3. If the telltales remain ON with no DTCs set after the drive cycle, disconnect the battery for at least 60 seconds then reconnect the battery.

4. Operate the vehicle at speeds greater than 40 km/h (25 mph), the EBCM should request all telltale indicators to turn OFF.

Diagnostic Aids

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

* DTC C0161 will be set if the brake is applied for 60 seconds while at speeds greater than 10 km/h (6 mph), such as a two footed driving.

Reference Information

Schematic Reference

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

* Exterior Lights Schematics Exterior Lights Schematics

Connector End View Reference

Component Connector End Views A/C Compressor Clutch

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 Programming and Relearning for scan tool information

Circuit/System Verification

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