2010 Cadillac Truck Escalade RWD V8-6.0L Hybrid Page 897
maintain proper battery voltage during this procedure.
1. Verify that no other EBCM DTCs are set.
瀚慖f DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code Descriptions/Diagnostic Trouble
Code (DTC) List - Vehicle).
2. Ignition ON, engine OFF, using a scan tool access the EBCM, Module Setup screen, and perform the EBCM Relearn. The relearn procedure
will verify valve and pressure sensor calibrations are correct.
Note: To ensure the complete brake modulator and high pressure accumulator pressure relief procedure is allowed to occur; the brake
controller must see one brake pedal apply with the engine running followed by a proper shutdown without applying the brake pedal.
3. Transmission in PARK, engine running, apply and release the brake pedal.
Note: The ignition must transition to the OFF position without pausing at ACCESSORY and without applying the brake pedal. This ensures
that the brake modulator and high pressure accumulator pressure relief occurs. This process will take approximately 1-2 minutes.
4. Ignition OFF, key removed from the ignition, wait 2 minutes.
Note: The ignition must remain in the ON position with the engine OFF during the following steps.
5. Ignition ON, brake pedal released, verify the following EBCM scan tool parameters are within the specified range:
* BMC Prim. Piston Pos. Sen. 5 V Reference Position - Between 4.75-5.25 V
* BMC Primary Piston Position Sensor A - Between 0.4-0.8 V
* BMC Primary Piston Position Sensor B - Between 4.2-4.6 V
瀚慖f any of the parameters are not within the specified range, refer to DTC C0277, C120C, C129A, C129B, C129D, C129E, C12B1, or
C12F8 (See: C Code Charts/C0277/Antilock Brake System - Hybrid (HP2)).
6. Brakes not applied, verify the following EBCM scan tool parameters are within the specified range:
* Master Cylinder Pressure Sensor Input - Less than 100 kPa (15 psi)
* Rear Brake Pressure Sensor - Less than 100 kPa (15 psi)
* Brake Pressure Sensor Input - Less than 100 kPa (15 psi)
* Accum. Pressure Sensor - Less than 800 kPa (116 psi)
瀚慖f any of the parameters are not within the specified range, replace the brake pressure modulator valve.
7. Perform a hydraulic check, refer to Brake Hydraulic and Assist System Diagnosis (Two-mode Hybrid) (See: Brakes and Traction
Control/Hydraulic System/Testing and Inspection/Component Tests and General Diagnostics/Brake Hydraulic and Assist System Diagnosis
(Two-mode Hybrid)).
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* Brake Pressure Modulator Valve Replacement (See: Brakes and Traction Control/Antilock Brakes / Traction Control Systems/Hydraulic
Control Assembly - Antilock Brakes/Service and Repair)
* Control Module References (See: Testing and Inspection/Programming and Relearning) for EBCM replacement, setup, relearn and
programming
C12F2
DTC C056D, C120C, C121C, C121E, C121F, C123A-C1256, C126E-C127C, C12C2-C12DB, C12DE, C12DF, or C12F2-C12F6
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
Instructions) provide an overview of each diagnostic category.
