Brake Pressure Modulator Valve (BPMV) Replacement
Removal Procedure
Caution
For safety reasons, the brake pressure modulator valve assembly must not be repaired, the complete unit must be replaced. With the exception of the EBCM, no screws on the brake pressure modulator valve assembly may be loosened. If screws are loosened, it will not be possible to get the brake circuits leak-tight and personal injury may result.
# Turn OFF the ignition.
Important
the area around the electronic brake control module (EBCM)/brake pressure modulator valve (BPMV) must be free from dirt to prevent contamination of disassembled ABS components.
# Thoroughly wash all contaminants from around the EBCM/BPMV.
# Remove the EBCM connector position assurance (2) from the EBCM electrical connector (1).
# Rotate the EBCM connector tab up to the unlocked position.
Notice
To prevent equipment damage, never connect or disconnect the wiring harness connection from the EBCM with the ignition switch in the ON position.
# Remove the EBCM electrical connector (1) from the EBCM (4).
Caution
Brake fluid may irritate eyes and skin. In case of contact, take the following actions:
* Eye contact--rinse thoroughly with water.
* Skin contact--wash with soap and water.
* If ingested--consult a physician immediately.
Notice
When removing the brake pressure modulator valve, protect the vehicle exterior from possible brake fluid spillage. Brake fluid can cause damage to painted surfaces.
Notice
Excessive bending of brake pipes during BPMV removal or installation may cause permanent damage that will require replacement.
Important
Record the location of all brake pipes to the BPMV for use as an aid during installation.
# Remove the 2 master cylinder brake pipes (1) from the BPMV (2).
Remove the 4 wheel brake pipes (1) from the BPMV (2).
# Clean any brake fluid spillage from the BPMV (1).
# Remove the 2 BPMV bracket nuts (2).
# Remove the EBCM/BPMV assembly (1) from the BPMV bracket (3).
Remove the BPMV electrical connector (2) from the EBCM (3)
Remove the 6 EBCM to BPMV screws (2).
13. Clean the surface of the EBCM/BPMV assembly.
Important
The EBCM cannot be repaired. If faulty, the unit must be replaced.
14. Separate the EBCM (2) from the BPMV (1).
Installation Procedure
# Clean the surface of the BPMV.
# Install the EBCM (2) to the BPMV (1).
Notice
Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.
# Install the 6 EBCM to BPMV screws (2).
Tighten
Tighten the 6 screws to 3.2 N·m (28 lb in).
# Install the BPMV electrical connector (2) to the EBCM (3).
Important
Make sure that all 3 rubber isolators are installed on the BPMV. The isolators protect the EBCM/BPMV assembly from vehicle vibrations.
# Install the EBCM/BPMV assembly (1) to the BPMV bracket (3).
Notice
Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.
# Install the 2 BPMV bracket nuts (2).
Tighten
Tighten the 2 nuts to 10 N·m (89 lb in).
Caution
The brake pipes must be fully installed to the brake pipe mounting retainers on the frame. Failure to properly retain the brake pipes may cause the pipes to contact the frame and/or the transmission resulting in possible loss of brake fluid and personal injury.
Caution
Make sure brake pipes are correctly connected to BPMV. If brake pipes are switched by mistake Inlet vs. Outlet, wheel lockup will occur and personal injury may result.
Important
If a new BPMV is being installed, remove the shipping plugs from the valve openings.
# Install the 4 wheel brake pipes (1) to the BPMV (2) using the locations recorded during the removal procedure.
Tighten
Tighten the 4 brake pipes to 15 N·m (11 lb ft).
# Install the 2 master cylinder brake pipes (1) to the BPMV (2) using the locations recorded during the removal procedure.
Tighten
Tighten the 2 brake pipes to 15 N·m (11 lb ft).
Notice
To prevent equipment damage, never connect or disconnect the wiring harness connection from the EBCM with the ignition switch in the ON position.
# Install the EBCM electrical connector (1) to the EBCM (4).
10. Rotate the EBCM connector tab (2) down to the locked position.
11. Install the connector position assurance (2) to the EBCM electrical connector (1).
12. Fill and bleed the hydraulic brake system. Refer to Master Cylinder Reservoir Filling and Hydraulic Brake System Bleeding in Hydraulic Brakes.
13. Perform the Auto Bleed Procedure. Refer to ABS Automated Bleed Procedure .
14. Perform the ABS Diagnostic System Check. Refer to Diagnostic System Check - ABS .
ABS Automated Bleed Procedure
Bleeding the ABS System
Perform a manual or pressure bleeding procedure. Refer to Hydraulic Brake System Bleeding in Hydraulic Brakes. If the desired brake pedal height results are not achieved, perform the automated bleed procedure below.
The procedure cycles the system valves and runs the pump in order to purge the air from the secondary circuits normally closed off during normal base brake operation and bleeding. The automated bleed procedure is recommended when air ingestion is suspected in the secondary circuits, or when the BPMV has been replaced.
Automated Bleed Procedure
Notice
The Auto Bleed Procedure may be terminated at any time during the process by pressing the EXIT button. No further Scan Tool prompts pertaining to the Auto Bleed procedure will be given. After exiting the bleed procedure, relieve bleed pressure and disconnect bleed equipment per manufacturers instructions. Failure to properly relieve pressure may result in spilled brake fluid causing damage to components and painted surfaces.
1. Raise the vehicle on a suitable support. Refer to Lifting and Jacking the Vehicle in General Information.
2. Remove all four tire and wheel assemblies. Refer to Tire and Wheel Removal and Installation in Tires and Wheels.
3. Inspect the brake system for leaks and visual damage. Refer to Brake Fluid Loss or Symptoms - Hydraulic Brakes in Hydraulic Brakes. Repair or replace as needed.
4. Inspect the battery state of charge. Refer to Battery Inspection/Test in Engine Electrical.
5. Install a scan tool.
6. Turn ON the ignition, with the engine OFF.
7. With the scan tool, establish communications with the EBCM. Select Special Functions. Select Automated Bleed from the Special Functions menu.
8. Bleed the base brake system. Refer to Hydraulic Brake System Bleeding in Hydraulic Brakes.
9. Follow the scan tool directions until the desired brake pedal height is achieved.
10. If the bleed procedure is aborted, a malfunction exists. Perform the following steps before resuming the bleed procedure:
* If a DTC is detected, refer to Diagnostic Trouble Code (DTC) List and diagnose the appropriate DTC.
* If the brake pedal feels spongy, perform the conventional brake bleed procedure again. Refer to Hydraulic Brake System Bleeding in Hydraulic Brakes.
11. When the desired pedal height is achieved, press the brake pedal in order to inspect for firmness.
12. Remove the scan tool.
13. Install the tire and wheel assemblies. Refer to Tire and Wheel Removal and Installation in Tires and Wheels.
14. Inspect the brake fluid level. Refer to Master Cylinder Reservoir Filling in Hydraulic Brakes.