DTC C0278, C129C, or C129F. Cadillac Escalade ESV 2009

For 1990-2009 cars only

Makes 🢒 Cadillac 🢒 2009 🢒 Escalade ESV 🢒 Brakes 🢒 Antilock Brake System - Hybrid (HP2) 🢒 DTC C0278, C129C, or C129F

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 Descriptors

DTC C0278 00: BMC Primary Piston Position Sensor Not Calibrated

DTC C129C: BMC Primary Piston Position Sensor Not Calibrated

DTC C129F: BMC Primary Piston Position Sensor Not Calibrated

The electronic brake control module (EBCM) uses input from the brake master cylinder piston position sensor and the brake switch to determine when the brake pedal is being applied and with how much force. These inputs are used to determine the driver's braking intent which is used to the control amount of pressure applied to the wheels..

Conditions for Running the DTC

•	Ignition ON.

•	Ignition voltage is greater than 10 volts.

Conditions for Setting the DTC

The BMC primary piston position relearn procedure has not been performed.

Action Taken When the DTC Sets

•	The EBCM disables the antilock brake system (ABS), traction control and the vehicle stability enhancement system (VSES) 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.

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 C0278, C129C or C129F are not set.

⇒	If any of the DTCs are set perform the EBCM, module setup, BMC primary piston position relearn.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for EBCM replacement, setup, and programming