Pacifica 2006-2008

Integrated Control Unit

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Removal & Installation



  1. Disconnect the negative battery cable from battery post and isolate.
    WARNING
    Vacuum in power brake booster must be pumped down (removed) before removing the master cylinder from the power brake booster. This is necessary to prevent power brake booster from sucking in any contamination as the master cylinder is removed. This can be done simply by pumping the brake pedal, with the engine not running, until a firm feeling brake pedal is achieved.

  2.  
  3. With the engine not running, pump the brake pedal until a firm pedal is achieved (4-5 strokes).
  4.  
  5. Remove nuts fastening coolant recovery bottle in place and reposition the bottle with the hoses out of the way.
    WARNING
    Before removing the master cylinder from the power brake vacuum booster, the master cylinder and vacuum booster must be thoroughly cleaned. This must be done to prevent dirt particles from falling into the power brake vacuum booster.

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  7. Thoroughly clean all surfaces of brake fluid reservoir and master cylinder, paying special attention to the area where the master cylinder attaches to the power brake booster.
  8.  
  9. Disconnect the wiring harness connector from the brake fluid level switch in master cylinder brake fluid reservoir.

    Click image to see an enlarged view

    Fig. View of master cylinder, sensor wiring harness connector, booster, mounting nut

  10.  
  11. Disconnect the primary and secondary brake tubes coming from the master cylinder at the ICU. Cap off the brake tubes and install sealing plugs in the open brake tube outlet ports of the ICU.

    Click image to see an enlarged view

    Fig. View of ICU, master cylinder, primary brake tube, and secondary brake tube

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  13. Remove the two nuts attaching the master cylinder to the power brake booster.
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  15. Slide the master cylinder straight out of the power brake booster, then remove.
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  17. Disconnect the four Chassis brake tubes at the ICU. Cap off the brake tubes and install sealing plugs in the open brake tube outlet ports of the ICU.

    Click image to see an enlarged view

    Fig. View of ICU, left front chassis brake tube, right front chassis brake tube, left rear chassis brake tube, and right rear chassis brake tube

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  19. Disconnect the 47-way connector from the Antilock Brake Module (ABM) by depressing the tabs on each side of the connector cover, then pulling outward and upward on the lower half of the cover until it locks into position pointing straight outward. Then pull the connector straight outward off the ABM.

    Click image to see an enlarged view

    Fig. View of ABM connector release tabs



    Click image to see an enlarged view

    Fig. View of wiring harness connector at ABM

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  21. Loosen the two bolts fastening the ICU bracket to frame rail.
  22.  
  23. Lift the ICU off the frame rail bolts and remove from vehicle.
  24.  

To install:

  1. Place the ICU with the mounting bracket over the two mounting bolts in the frame rail. Tighten the bolts to 18 ft. lbs. (24 Nm).
  2.  
  3. With the connector cover completely open, install the 47-way wiring connector into the socket of the ABM and close cover, locking the connector in place.
  4.  
  5. Install the four chassis brake tubes into the outlet ports of the ICU, being sure to connect the correct tube to the correct port. Tighten the brake tube nuts to 120 in. lbs. (14 Nm).
    WARNING
    The seal on rear of master cylinder is used to create seal for holding vacuum in power brake vacuum booster. Vacuum seal on master cylinder MUST be replaced whenever master cylinder is removed from power brake vacuum booster.

  6.  
  7. Remove the vacuum seal located on the mounting flange of the master cylinder by carefully pulling it off the rear of the master cylinder. Do not attempt to pry seal off the master cylinder by inserting a sharp tool between the seal and master cylinder casting.
  8.  
  9. Install a NEW vacuum seal on the rear of the master cylinder, making sure the seal fits squarely in the mounting groove.
  10.  
  11. Position the master cylinder on the studs of the power brake booster, aligning the booster push rod with the master cylinder piston.
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  13. Install the two master cylinder mounting nuts. Tighten both mounting nuts to 225 inch lbs. (25 Nm).
  14.  
  15. Thread the primary and secondary brake tubes into the ICU ports. The brake tubes must be held securely when tightened to control the orientation of the flex section. Tighten the tube nuts to 120 inch lbs. (14 Nm).
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  17. Connect the wiring harness connector to the brake fluid level switch mounted in brake fluid reservoir.
  18.  
  19. Place the coolant recovery bottle in its normal mounted position and install the nuts fastening it in place.
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  21. Connect the negative battery cable to battery post.
  22.  
  23. Hook up scan tool to initialize the ABM.
  24.  
  25. Fill the master cylinder with clean, fresh brake fluid, then bleed the base brakes and ABS.
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  27. Road test vehicle to ensure proper operation of brakes.
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  1. Disconnect the negative battery cable from battery post and isolate.
  2.  
  3. Using a brake pedal holding tool, depress the brake pedal past its first inch of travel and hold it in this position. Holding the pedal in this position will isolate master cylinder from hydraulic brake system and will not allow brake fluid to drain out of brake fluid reservoir while brake lines are open.

    Click image to see an enlarged view

    Fig. Use brake pedal holding tool as indicated

  4.  
  5. Disconnect the primary and secondary brake tubes coming from the master cylinder at the ICU. Cap off the brake tubes and install sealing plugs in the open brake tube outlet ports of the ICU.

    Click image to see an enlarged view

    Fig. View of ICU, with primary and secondary brake tubes

  6.  
  7. Disconnect the four chassis brake tubes at the ICU. Cap off the brake tubes and install sealing plugs in the open brake tube outlet ports of the ICU. .

    Click image to see an enlarged view

    Fig. Disconnect four chassis brake tubes from ICU

  8.  
  9. Disconnect the wiring connector from the Antilock Brake Module (ABM) by depressing the tab in the center of the connector and then lifting the release lever, rotating it upward to the top of the connector, or until the connector is fully released from the module socket.

    Click image to see an enlarged view

    Fig. Depress ABS wiring connector tab, lift the release lever, and rotate upward



    Click image to see an enlarged view

    Fig. View of ABM and wiring connector

  10.  
  11. Loosen the two bolts fastening the ICU bracket to frame rail.
  12.  
  13. Lift the ICU off the frame rail bolts and remove from vehicle.

    Click image to see an enlarged view

    Fig. Loosen bolts, and remove ICU

  14.  

To install:

  1. Place the ICU with the mounting bracket over the two mounting bolts in the frame rail. Tighten the bolts to 18 ft. lbs. (24 Nm).
  2.  
  3. Install the ABM wiring connector into the socket of ABM.
    NOTE
    To connect the ABM wiring connector to the ABM, begin with the release lever in the full upward (released) position. Push the connector onto the ABM socket and rotate the release lever downward until it snaps into place in the locked position below the release tab.

  4.  
  5. Install the four chassis brake tubes into the outlet ports of the ICU, being sure to connect the correct tube to the correct port. Tighten the brake tube nuts to 120 in. lbs. (14 Nm).

    Click image to see an enlarged view

    Fig. Install the correct brake tube in the correct port on the ICU. The brake tubes going to the wheel brakes are as follows: right front, left rear, right rear, left front

  6.  
  7. Thread the primary and secondary brake tubes into the ICU ports. The brake tubes must be held securely when tightened to control orientation of flex section. Tighten the tube nuts to 120 inch lbs. (14 Nm).

    Click image to see an enlarged view

    Fig. Thread the primary and secondary brake tubes into ICU ports as indicated

  8.  
  9. Remove the brake pedal holding tool.
  10.  
  11. Connect the negative battery cable to battery post.
  12.  
  13. Fill the master cylinder with clean, fresh brake fluid, then bleed the base brakes and ABS.
  14.  
  15. Hook up scan tool to initialize the ABM and perform the following:

    Clear any faults.
     
    Perform the ABS Verification Test and road test the vehicle to ensure proper operation of brakes.
     

  16.  


NOTE
The Hydraulic Control Unit (HCU) and the Antilock Brake Module (ABM) used with this antilock brake system are combined (integrated) into one unit, which is called the Integrated Control Unit (ICU). The ICU is located below the master cylinder in the engine compartment. It is mounted to the left frame rail.


NOTE
The replaceable components of the ICU are the HCU and the ABM. No attempt should be made to service any individual components of the HCU or ABM.

 
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