Control Module, Separating From Hydraulic Unit: Procedure

2025 Audi A4 Quattro PrestigeSECTION Procedure

-- Remove the hydraulic control unit. Refer to ABS Control Module -J104- / ABS Hydraulic Unit -N55-, REMOVING AND INSTALLING .

CAUTION:

There is a risk of destroying the control module through the electrostatic charge and reduced cleanliness.

- Discharge electrostatic charge: touch the electro-static discharge work surface

- Protect the inner control module from moisture and dirt.

-- Place the hydraulic unit with the control module on the ESD Work Surface:VAS 6613  .

  • The control module -2- faces upward and the hydraulic unit -4- with the pump motor and connector -3- faces down.
    Fig 1: Identifying Hydraulic Unit
    GWWA45-10118Courtesy of AUDI OF AMERICA, LLC

-- Remove the bolts -1- and dispose of them.

-- Carefully remove the control module vertically upward without tilting.

  • Blowing the control module or hydraulic unit out with compressed air is not permitted.
  • The valve bodies inside the hydraulic unit must not be damaged or bent.

-- Cover the open hydraulic unit with a lint-free cloth.

-- Check the hydraulic unit sealing surface, and if necessary, clean with mineral spirits and a lint-free cloth.

-- A damaged sealing surface must not be mechanically reworked. A hydraulic unit with a damaged sealing surface must be replaced.

CAUTION:

There is a risk of damaging the control module through improper handling.

- Do not lift or remove the seal.

RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.