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 Braking System Brake Switch Circuit Not PlausibleCircuit/System Description
The body control module (BCM) monitors the brake pedal position sensor and sends a serial data message when the brake pedal is applied. When the vehicle is stopping, the electronic brake control module (EBCM) monitors for the brake pedal applied serial data message from the BCM, with the brake pressure increasing and the vehicle slowing down, or when the vehicle is accelerating, the brake pedal is not applied and brake pressure is not increasing.
Conditions for Running the DTC
Ignition ON.
Conditions for Setting the DTC
| • | The EBCM detects 4 accelerations from standstill to a vehicle speed greater 40 km/h (26 MPH) without any brake light switch signal changes. |
| • | The EBCM detects the vehicle speed is greater than 20 km/h (13 MPH), the brake pedal is applied for 360 s, and brake pressure is less than 15 bar (218 PSI). |
Conditions for Clearing the DTC
A current DTC clears when the diagnostic runs and passes.
Diagnostic Aids
The DTC C0161 5A can be set if the brake pedal is applied while accelerating or the brake pedal position sensor is out of adjustment.
Reference Information
Schematic Reference
Antilock Brake System Schematics
Connector End View Reference
Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Ignition ON, observe the stop lamps while applying and releasing the brake pedal. Verify the stop lamps operate properly.
| ⇒ | If the stop lamps do not operate properly, refer to Symptoms - Lighting |
Circuit/System Testing
Replace the K17 Electronic Brake Control Module (EBCM) and verify the DTC does not reset.
| ⇒ | If the DTC resets replace the K9 Body Control Module (BCM). |
Repair Instructions
| • | Perform the Diagnostic Repair Verification after completing the diagnostic procedure. |
| • | Control Module References for control module replacement, setup and programming |
