GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

Caution: The high pressure accumulator (HPA) and the chambers of the brake modulator assembly to which it attaches, store brake fluid at extremely high pressures. Fluid pressure must be relieved before attempting to service the HPA. Ensure that the recommended procedures are followed to relieve system pressure, including using the manual pressure release steps. Failure to properly follow procedures to depressurize the system may result in personal injury.

Caution: Refer to Brake Fluid Irritant Caution in the Preface section.

Notice: Refer to Brake Fluid Effects on Paint and Electrical Components Notice in the Preface section.

Notice: Always connect or disconnect the wiring harness connector from the EBCM/EBTCM with the ignition switch in the OFF position. Failure to observe this precaution could result in damage to the EBCM/EBTCM.

Important: The ignition must be in the OFF position, without pausing at ACCESSORY, and without applying the brake pedal to ensure the brake modulator and high pressure accumulator (HPA) pressure relief occurs. This process will take approximately 1-3 minutes.

  1. Turn the ignition to OFF, without pausing at ACCESSORY, and without applying the brake pedal.
  2. Remove the ignition key.

  3. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle.

  4. Object Number: 1965624  Size: SH
  5. Remove the antilock brake system (ABS) module splash shield retainers (1).

  6. Object Number: 1965625  Size: SH
  7. Remove the ABS module splash shield bolts (1).

  8. Object Number: 1965627  Size: SH
  9. Remove the ABS module splash shield (1).
  10. Clean all dirt and debris from the brake pressure modulator valve (BPMV) assembly and the brake pipe fittings.

  11. Object Number: 2037952  Size: SH

    Important: To ensure brake modulator and HPA pressure relief has occurred, the manual pressure relief valve must be opened momentarily.

  12. Loosen the brake modulator manual pressure relief valve (1) ¼ turn counterclockwise.
  13. Seat, but do not tighten, the manual pressure relief valve.

  14. Object Number: 1965631  Size: SH
  15. Disconnect the electronic brake control module (EBCM) electrical connector.
  16. Disconnect the electronic brake control position sensor electrical connector.
  17. Disconnect the BPMV supply hose quick connect (1).
  18. Cap the BPMV inlet port and plug the supply hose to prevent brake fluid loss and contamination.


    Object Number: 1965632  Size: SH
  19. Disconnect the BPMV return hose quick connect (1).
  20. Cap the BPMV outlet port and plug the return hose to prevent brake fluid loss and contamination.


    Object Number: 1965634  Size: SH
  21. Disconnect the RR brake pipe fitting (1).
  22. Cap the brake pipe fitting and plug the BPMV outlet port to prevent brake fluid loss and contamination.


    Object Number: 1965636  Size: SH
  23. Disconnect the LR brake pipe fitting (1).
  24. Cap the brake pipe fitting and plug the BPMV outlet port to prevent brake fluid loss and contamination.


    Object Number: 1965637  Size: SH
  25. Disconnect the primary brake pipe fitting (1).
  26. Cap the brake pipe fitting and plug the BPMV inlet port to prevent brake fluid loss and contamination.


    Object Number: 1965640  Size: SH
  27. Disconnect the RH supply brake pipe fitting (1).
  28. Cap the brake pipe fitting and plug the BPMV outlet port to prevent brake fluid loss and contamination.


    Object Number: 1965641  Size: SH
  29. Disconnect the LH supply brake pipe fitting (1).
  30. Cap the brake pipe fitting and plug the BPMV outlet port to prevent brake fluid loss and contamination.


    Object Number: 1965643  Size: SH

    Important: It is not necessary to remove the BPMV bracket bolts.

  31. From the outboard of the vehicle frame, access and loosen the 3 BPMV bracket bolts (1).

  32. Object Number: 1965644  Size: SH
  33. Slide the EBCM/BPMV and bracket assembly (1) toward the front of the vehicle and remove the assembly from the vehicle frame.
  34. Place the EBCM/BPMV and bracket assembly on a clean work surface.

  35. Object Number: 1965646  Size: SH
  36. Remove the 2 BPMV bolts (1).

  37. Object Number: 1965647  Size: SH
  38. Remove the BPMV assembly from the bracket (1).
  39. Remove the sleeves and insulators from the BPMV, if necessary.

  40. Object Number: 2077050  Size: SH
  41. If replacing the BPMV, loosen but do not remove the EBCM bolts (1).

  42. Object Number: 2077051  Size: SH

    Important: Do not pry the EBCM from the BPMV. The EBCM must be pulled back evenly.

  43. Using the loosened bolts as a guide, carefully pull the EBCM (1) evenly from the BPMV to release the electrical connectors.

  44. Object Number: 2077054  Size: SH
  45. Remove the EBCM bolts (1).

  46. Object Number: 2077055  Size: SH
  47. Remove the EBCM (1).

Installation Procedure


    Object Number: 1965651  Size: SH
  1. Install the EBCM (1) to the BPMV, if removed.
  2. Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 1965650  Size: SH
  3. Install the EBCM bolts (1).
  4. Tighten
    Tighten the bolts in an X pattern to 3 N·m (27 lb in).


    Object Number: 1965647  Size: SH
  5. Install the sleeves and insulators to the BPMV, if removed.
  6. Install the BPMV assembly to the bracket (1).

  7. Object Number: 1965646  Size: SH
  8. Install the 2 BPMV bolts (1).
  9. Tighten
    Tighten the bolts to 9 N·m (80 lb in).


    Object Number: 1965644  Size: SH
  10. Position the hydraulic control unit and bracket assembly (1)  to the frame rail. Slide the assembly toward the rear of the vehicle and install the assembly to the vehicle frame.

  11. Object Number: 1965643  Size: SH
  12. From the outboard of the vehicle frame, access and tighten the 3 BPMV bracket bolts (1).
  13. Tighten
    Tighten the bolts to 22 N·m (16 lb ft).


    Object Number: 1965641  Size: SH
  14. Connect the LH supply brake pipe fitting (1).
  15. Tighten
    Tighten the fitting to 18 N·m (13 lb ft).


    Object Number: 1965640  Size: SH
  16. Connect the RH supply brake pipe fitting (1).
  17. Tighten
    Tighten the fitting to 18 N·m (13 lb ft).


    Object Number: 1965637  Size: SH
  18. Connect the primary brake pipe fitting (1).
  19. Tighten
    Tighten the fitting to 18 N·m (13 lb ft).


    Object Number: 1965636  Size: SH
  20. Connect the LR brake pipe fitting (1).
  21. Tighten
    Tighten the fitting to 18 N·m (13 lb ft).


    Object Number: 1965634  Size: SH
  22. Connect the RR brake pipe fitting (1).
  23. Tighten
    Tighten the fitting to 18 N·m (13 lb ft).


    Object Number: 1965632  Size: SH
  24. Connect the BPMV return hose quick connect (1).
  25. Ensure the return hose quick connect is fully engaged by attempting to pull the return hose from the outlet fitting.


    Object Number: 1965631  Size: SH
  26. Connect the BPMV supply hose quick connect (1).
  27. Ensure the supply hose quick connect is fully engaged by attempting to pull the supply hose from the inlet fitting.

  28. Connect the EBCM electrical connector.
  29. Connect the electronic brake control position sensor electrical connector.

  30. Object Number: 2037952  Size: SH
  31. Tighten the brake modulator manual pressure relief valve (1).
  32. Tighten
    Tighten the valve to 40 N·m (30 lb ft).


    Object Number: 1965627  Size: SH
  33. Install the ABS module splash shield (1).

  34. Object Number: 1965625  Size: SH
  35. Install the ABS module splash shield bolts (1).
  36. Tighten
    Tighten the bolts to 20 N·m (15 lb ft).


    Object Number: 1965624  Size: SH
  37. Install the ABS module splash shield retainers (1).
  38. If installing a new EBCM, the EBCM must be programmed. Refer to Control Module References.
  39. Perform the Antilock Brake System Automated Bleed Procedure.
  40. Follow the procedure completely to ensure the sensor and boost valve calibration and EBCM learn processes have been completed.