For 1990-2009 cars only
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 00: Antilock Brake System (ABS) Brake Switch/Sensor Circuit not Plausible.Circuit/System Description
The brake pedal position (BPP) sensor is an input to the body control module (BCM). The BCM then sends a serial data message to the electronic brake control module (EBCM) and other electronic control modules. The BPP sensor is a potentiometer type sensor with a 5-volt reference circuit and a low reference circuit. The instrument panel module (IPM) supplies the 5-volt reference to the BPP.
Conditions for Running the DTC
| • | The ignition is ON. |
| • | The vehicle speed is greater than 16 km/h (10 mph). |
| • | The ignition voltage is greater than 9.5 volts. |
Conditions for Setting the DTC
| • | The brake pedal is sensed as applied. |
| • | The vehicle speed is greater than 40 km/h (25 mph). |
| • | The vehicles acceleration exceeds 8 km/h per second (5 mph per second). |
| • | Brake pedal is not applied. |
| • | Master cylinder pressure is greater than 150 psi. |
| • | The vehicle speed is greater than 24 km/h (14 mph). |
| • | The vehicles deceleration exceeds 11.5 km/h per second (7 mph per second). |
Action Taken When the DTC Sets
The ABS/TCS/ESC remains functional.
Conditions for Clearing the DTC
| • | The condition for the DTC is no longer present and the DTC is cleared with a scan tool. |
| • | The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles. |
Diagnostic Aids
The DTC C0161 00 can be set if the vehicle has been driven with the brake applied during acceleration.
Reference Information
Schematic Reference
Antilock Brake System Schematics
Connector End View Reference
Description and Operation Reference
Electrical Information Reference
Scan Tool Reference
Circuit/System Verification
With the ignition ON, use a scan tool to display DTCs for the BCM.
| ⇒ | If DTC C0277 or C0278 are present, go to Diagnostic System Check - Vehicle. |
| ⇒ | If no DTCs are present, go to Diagnostic Aids. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
