GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2005 🢒 CTS 🢒 DTC 🢒 DTC C0163 or C0164

Diagnostic Instructions

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

DTC Descriptor

DTC C0163 : ABS/TCS/Brake Switch Sensor Circuit Low

DTC C0164: ABS/TCS/Brake Switch Sensor Circuit High

Circuit/System Description

The brake pedal position sensor (BPP) is an input to the electronic brake control module (EBCM). The brake pedal position sensor is a potentiometer type sensor with a 5-volt reference circuit and a low reference circuit. The BCM supplies the 5-volt reference to the BPP.

Conditions for Running the DTC
    • Ignition ON.
    • Vehicle Speed greater than 15 mph.
    • The BPP is an unapplied state

Conditions for Setting the DTC

The EBCM detects the vehicle speed greater than 24 km/h (15 mph), the BPP is Unapplied, and 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 100 consecutive drive cycles.

Diagnostic Aids
    • A signal circuit of the brake pedal position sensor is open.
    • The BPP sensor is misadjusted/binding or needs calibration.
    • All brake lamps are open.
    • All brake lamp grounds are open.
    • An internal EBCM problem.

Reference Information

Schematic Reference

Antilock Brake System Schematics

Connector End View Reference

Antilock Brake System Connector End Views

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

Scan Tool Data List for scan tool information

Circuit/System Verification
  1. Verify that DTC C0277, C0297, or B3445 is not set.
    2. ⇒ If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle.
  2. Ignition ON, observe the scan tool EBCM BPP parameter while applying and releasing the brake pedal. The reading should change between Applied and Released.
    3. ⇒If the parameter does not change between applied and release, Check the BPP sensor for being misadjusted or binding.
  3. Replace the BPP. If the DTC resets, replace the EBCM.

Repair Instructions
    •  Brake Pedal Position Sensor Replacement
    •  Electronic Brake Control Module Replacement for EBCM replacement, setup, and programming