GM 12226953
Control Module

Before starting an ABS Control Module (ABSCM) replacement procedure the ignition must be turned off while simultaneously raising and supporting the vehicle. Begin by removing the tire and wheel from the left front position and then separate the left front fascia extension. Clean away loose dirt from the abscm area so disassembled antilock brake system components stay contamination-free and then wipe all abscm mounting space clean. Remove the abscm connector position assurance from its electrical connector then turn the abscm connector tab until it unlocks its position. Connectors between the abscm and wiring harness should never operate when the Ignition Switch is in on position because it would damage equipment. Remove the abscm electrical connector and brake pressure modulator valve (BPMV) electrical connector which ABS Control Module (ABSCM) connects to. Clean the surface that connects the abscm with the bpmv after removing all 6 abscm to bpmv screws. Replacement of the abscm is needed whenever it proves faulty because this unit is beyond repair. The abscm needs to be detached from the bpmv. Before abscm installation you must wash the sealing area of the bpmv then position the abscm onto the bpmv. Insert the 6 abscm to bpmv screws then tighten each one to 3.2 nm (28 inch lbs.). The next step is connecting the electrical connector of bpmv to the abscm while keeping the Ignition Switch off to avoid damaging equipment. The abscm connector tab should be rotated downward until it reaches a locked position before you install the abscm connector position assurance onto the abscm electrical connector. After reinstalling the left front fascia extension the team should install the left front wheel followed by lowering the vehicle. Unprogrammed abscm can result in system malfunctions that affect dynamic rear proportioning (DRP) among other systems along with setting dtc c1248 or c1255. All new abscms need programming with the latest software which matches the vehicle specifications. After using a diagnostic tool to clear the dtcs proceed with hydraulic brake system filling, bleeding and autonomic bleeding before performing the abs diagnostic system check.

Rotate the EBCM connector tab up to the unlocked position and remove the EBCM connector position assurance.

It may lead to inoperative or poorly functioning DRP/ABS/TCS/VSES/TIM/VES and may set DTC C1248 and C1255.

The complete unit must be replaced; it must not be repaired.

Turn OFF the ignition and raise the vehicle.

Turn OFF the ignition and raise the vehicle.

Lower the vehicle and, if a replacement EBCM is being installed, program it using the latest software matching the vehicle.

Remove the shipping plugs from the valve openings, then install the 4 wheel brake pipes to the BPMV using the recorded locations and tighten them to 15 Nm (11 ft. lbs.).

Clean the seal surface of the BPMV and secure the EBCM to the BPMV with the 6 EBCM to BPMV screws tightened to 3.2 Nm (28 inch lbs.).

DTC C1248 indicating the EBCM turned the red brake warning indicator on, or DTC C1255 indicating an internal malfunction.