2026-04-30

Car Computer (HW4) (Remove and Install)

Correction code 21151031 0.84 NOTE: Unless otherwise explicitly stated in the procedure, the correction code and FRT listed above reflect all of the work required to perform this procedure, including the linked procedures. Do not stack correction codes unless explicitly told to do so. NOTE: See Flat Rate Times to learn more about FRTs and how they are created. NOTE: See Personal Protection to make sure you are wearing proper PPE when performing the procedure below. NOTE: See Ergonomic Precautions for safe and healthy working practices.

  • 2026-04-28: Reorganized the whole procedure and added the coolant vacuum refill step to avoid overheating.
  • 2024-04-02: Added torque specification for the bolts that attach the car computer to the bulkhead, and added a step for the installation of such bolts.
  • For HW3 car computer, use correction code 21151001
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Warning
This procedure is a DRAFT. Although it has been validated, Warnings and Cautions might be missing. Follow safety requirements and use extreme caution when working on or near High Voltage systems and components.

Remove

  1. Open front doors and lower front windows.
  2. Unlock the vehicle gateway. See Gateway (Unlock).
  3. Perform the following routine using Service Mode or Toolbox (see 0005 - Service Modes): PROC_VCFRONT_X_START-THERMAL-FILL-DRAIN-COOLANTvia Toolbox:(link)
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    Note
    This routine has a time limit of 5 hours. If it takes longer than 5 hours, perform this step again.
  4. Disconnect the LV power. See 12V/LV Power (Disconnect and Connect)
  5. Remove the HEPA duct. See Duct - HEPA (Remove and Replace).
  6. Place absorbent material below the car computer coolant inlet and outlet to collect any spilled coolant.
  7. Remove car computer coolant plugs (x2) from the new car computer.
  8. Loosen the spring clips (x2) from the coolant hoses, and then release the hoses from the car computer.
  9. Install the car computer fluid port plug to the inlet and outlet of the car computer.
  10. Block the coolant hoses with the coolant hose plugs (x2).
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    Note
    No need to engage spring clips.
  11. Remove the bolts (x2) that attach the car computer to the bulkhead.
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    Note
    13 mm, 15 Nm
  12. Remove the glove box. See Glove Box - Without Knee Airbags (Remove and Replace) or Glove Box - With Knee Airbags (Remove and Replace).
  13. Remove the RH center console side panel carpet. See Side Panel - Center Console - LH (Remove and Replace)
  14. Remove the clip that attaches the RH front cabin carpet to the body, and then fold the RH front cabin carpet backwards.
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    Note
    Newer vehicles may be equipped with additional foam installed below carpet.
  15. Remove the RH footwell duct. See Duct - Footwell - RH (Remove and Replace).
  16. Remove the RH air wave duct. See Duct - Air Wave - RH (Remove and Replace).
  17. Remove the bolt that attaches the ground strap to the car computer.
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    Note
    1x bolt, T25, 4 Nm
  18. Release the harness connectors (x5) on the LH side of the car computer.
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    Note
    Release locks on connectors before removal.
  19. Disconnect the connectors (x2) on the front of the car computer.
  20. Remove the nuts (x2) that attach the car computer to the bulkhead.
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    Note
    13mm, 8 Nm
  21. Partially remove the car computer to access RH connectors.
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    Note
    Avoid straining harness.
  22. Release the connectors (x8) from the RH side of the car computer, and then remove the computer from the vehicle.
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    CAUTION
    Avoid spilling coolant on the electrical connectors.
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    Note
    Release locks on connectors if equipped before removal.
  23. Remove the board to board jumper from the car computer.
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    Note
    4x connectors, 1x harness clip, This will be installed on new car computer.

Install

  1. Install the board to board jumper on the car computer
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    Note
    4x connectors, 1x harness clip, Engage locking tabs.
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    Note
    If the old car computer has a removable SIM card, remove the SIM card from the old computer and install it to the new car computer.
  2. Connect the RH side connectors (x5) to the car computer.
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    Note
    Engage locks on connectors if equipped.
  3. Install the nuts (x2) that attach the car computer to the bulkhead.
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    Note
    13mm, 8 Nm
  4. Connect the front side connectors (x2) to the car computer.
  5. Connect the LH side connectors (x5) to the car computer.
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    Note
    Engage locking tabs if equipped
  6. Install the bolt that attaches the ground cable to the car computer (torque 4 Nm).
  7. Install the bolts (x2) that attach the car computer to the bulkhead.
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    Note
    13 mm, 15 Nm
  8. Remove the plugs (x2) from the car computer coolant hoses.
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    Note
    Engage spring clips after removal
  9. Attach the hoses to the car computer coolant inlet and outlet, and then engage the spring clips (x2).
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    Note
    Perform push-pull-push test to ensure the hoses are fully seated.
  10. Remove the absorbent material from below the car computer coolant inlet and outlet.
  11. Perform a cooling system vacuum refill. See Cooling System (Vacuum Refill).
  12. Install the fresh air intake duct. See Duct - HEPA (Remove and Replace).
  13. Install the HEPA filter. See Assembly - Filter - HEPA (Remove and Replace).
  14. Fold the RH front main cabin carpet back to its original position.
  15. Install the clip that attaches the RH front cabin carpet to the body.
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    Note
    1x clip
  16. Install the RH air wave duct. See Duct - Air Wave - RH (Remove and Replace).
  17. Install the RH footwell air duct. See Duct - Footwell - RH (Remove and Replace).
  18. Install the RH center console side panel carpet. See Side Panel - Center Console - LH (Remove and Replace)
  19. Install the glove box. See Glove Box - Without Knee Airbags (Remove and Replace) or Glove Box - With Knee Airbags (Remove and Replace).
  20. Raise front windows and close front doors.