DTC C0161. Cadillac CTS 2009

For 1990-2009 cars only

Makes 🢒 Cadillac 🢒 2009 🢒 CTS 🢒 Safety and Security 🢒 Supplemental Inflatable Restraints 🢒 DTC C0161

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 Descriptor

DTC C0161 5A : Antilock Brake System (ABS) Brake Switch Circuit Plausibility Failure

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.

•	Ignition voltage is greater than 10 volts.

Conditions for Setting the DTC

•	The EBCM detects the vehicle speed greater than 8 km/h (5 mph), the brake pedal is Applied for 1 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.

Actions Taken when the DTC Sets

•	The EBCM disables the traction control and StabiliTrak for the duration of the ignition cycle.

•	A DIC message and/or a warning indicator may be displayed.

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

The DTC C0161 5A can be set if the brake pedal is applied while accelerating.

Reference Information

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

Verify that DTC C0277 or C0278 is not set.

⇒	If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle.

Verify brake pedal linkage travel and switch adjustment.
Ignition ON, observe the scan tool EBCM BPP parameter while applying and releasing the brake pedal. The reading should change between Applied and Released.

⇒	If the parameter does not change between applied and release, replace the EBCM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

•	Brake Pressure Modulator Valve Replacement

•	Control Module References for EBCM replacement, setup, and programming