Brake Modulator Assembly Replacement

Brake Modulator Assembly Replacement (JL4)

Removal Procedure
Caution: Refer to Brake Fluid Irritant Caution (Brake Fluid Irritant Caution) .

Notice: Refer to Brake Fluid Effects on Paint and Electrical Components Notice (Brake Fluid Effects on Paint and Electrical Components Notice) .


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: This procedure applies to vehicles equipped with RPO JL4. The electronic brake control module (EBCM) and the brake pressure modulator valve (BPMV) must be replaced as an assembly and cannot be separated.



1. Turn the ignition switch to the OFF position.
2. Clean the brake pressure modulator assembly area of any accumulated dirt and foreign material.




3. Disconnect the brake fluid level indicator switch electrical connector.
4. Disconnect the vacuum brake booster vacuum sensor electrical connector.




5. Release the wiring harness retainer from the master cylinder mounting stud and position the wiring harness downward.
6. Remove and discard the 2 master cylinder nuts.
7. If equipped, disconnect the clutch master cylinder hose from the brake master cylinder reservoir.
Cap the brake fluid reservoir outlet and plug the clutch master cylinder hose inlet to prevent brake fluid loss and contamination.




8. Remove the 2 master cylinder brake pipe fittings from the brake modulator assembly.
Cap the brake pipe fittings and plug the BPMV inlet ports to prevent brake fluid loss and contamination.
9. Remove the brake master cylinder and master cylinder brake pipes as an assembly.




10. Remove the 2 rear brake pipe fittings (1) from the brake modulator assembly.
Cap the brake pipe fittings to prevent brake fluid loss and contamination.
11. Remove the 2 front brake pipe fittings (2) from the brake modulator assembly.
Cap the brake pipe fittings to prevent brake fluid loss and contamination.
12. Lift the locking tabs on the lower edge of the EBCM electrical connector (3) and disconnect the electrical connector.
13. Position the EBCM electrical connector and the wiring harness toward the front of the vehicle.




14. Remove the 2 upper brake modulator assembly bracket bolts (1).
15. Loosen, but do not remove the lower BPMV bracket bolt (2).
16. Remove the brake modulator and bracket assembly (3).




17. Remove the brake modulator assembly bolt.
18. Carefully separate the BPMV from the bracket. Do not pry against the accumulator covers on the underside of the brake modulator assembly.



Installation Procedure





1. Inspect the brake modulator assembly bracket insulators for damage and replace if necessary.

Important: If necessary, a small amount of denatured alcohol can be used as an assembly aid for installing the brake modulator assembly mounting pins to the brake modulator assembly bracket.


2. Install the brake modulator assembly to the bracket.

Notice: Refer to Fastener Notice (Fastener Notice) .

3. Install the brake modulator assembly bolt.

Tighten the bolt to 11 N.m (97 lb in).





4. Install the brake modulator and bracket assembly (3). Align the brake modulator assembly bracket to the lower bracket bolt (2).
5. Install the 2 upper brake modulator bracket bolts (1).

Tighten the bolts to 10 N.m (89 lb in).

6. Install the lower brake modulator bracket bolt.

Tighten the bolt to 10 N.m (89 lb in).





7. Install the 2 rear brake pipe fittings (1) to the brake modulator assembly.

Tighten the fittings to 20 N.m (15 lb ft).

8. Install the 2 front brake pipe fittings (2) to the brake modulator assembly.

Tighten the fittings to 20 N.m (15 lb ft).

9. Connect the EBCM electrical connector (3). Ensure the tabs on the cam lever are securely locked in place.




10. Install the brake master cylinder and brake pipes assembly to the vacuum brake booster.
11. Install the 2 master cylinder brake pipe fittings to the brake modulator assembly.

Tighten the fittings to 20 N.m (15 lb ft).





12. If equipped, connect the clutch master cylinder hose to the brake master cylinder reservoir.
13. Install 2 new brake master cylinder nuts.

Tighten the nuts to 20 N.m (15 lb ft).

14. Position the wiring harness upward and install the wiring harness retainer to the master cylinder mounting stud on the vacuum brake booster.




15. Connect the brake booster vacuum sensor electrical connector.
16. Connect the brake fluid level indicator switch electrical connector.
17. If a new brake modulator assembly was installed, program the brake modulator assembly. Refer to Electronic Brake Control Module Programming and Setup (Programming and Relearning) .

Important: A new brake modulator assembly comes with both the primary and secondary circuits pre-filled with brake fluid. If the ignition key has not been cycled after installation, only a base brake bleed is necessary.


18. Bleed the hydraulic brake system. Refer to Hydraulic Brake System Bleeding (Manual) (Service and Repair)Hydraulic Brake System Bleeding (Pressure) (Service and Repair) .
19. Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) .
20. Observe the brake pedal feel after performing the diagnostic system check. If the pedal now feels spongy, air may have been introduced into the secondary hydraulic circuit of the brake modulator which then may have been introduced into the primary circuit. If the pedal feels spongy, perform the Antilock Brake System Automated Bleed Procedure (Service and Repair) .