ABS Control Module -J104- /ABS Hydraulic Unit -N55-, REMOVING AND INSTALLING, LHD VEHICLES: Removing

WARNING: This page is about a different car, the 2023 Audi S3, 2023 Audi RS 3, 2023 Audi A3 Quattro, and 2023 Audi A3. However, it is still accessible from the selected car via links, so may be relevant.

-- If the ABS Control Module -J104- /the hydraulic control unit is replaced, select the "control module, replacing" program. Refer to DIAGNOSTIC ENTRIES .

-- Insert the Brake Pedal Actuator:V.A.G 1869/2 -item A- between the brake pedal and driver seat. Pretension the brake pedal at least 60 mm. (By doing this, the valves in the brake master cylinder are closed and the brake fluid reservoir does not run empty.)

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CAUTION:

Leaking brake fluid increases the risk of injury.

Risk of skin irritation and injury.

- Wear safety gloves.

TIP:

For certain tire combinations the removal of the wheels is required.

-- Remove the protective cap -3- from the bleed screw -1- on the left front caliper.

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-- Connect the collection bottle hose -2-.

-- Open the bleed screw to reduce the pressure in the brake system.

-- Close the bleed screw and remove the collection bottle.

-- Repeat the procedure on the left rear brake caliper.

Do not remove the Brake Pedal Actuator:V.A.G 1869/2 .

-- Remove the engine cover. Refer to ENGINE COVER, REMOVING AND INSTALLING .

Vehicle with TDI Engine:

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-- Remove the emissions control module. Refer to the appropriate Service Information. .

-- Remove the bolts -1- for the pendulum support.

Vehicle with 2.0L TFSI evo4:

-- Remove the particulate filter. Refer to CATALYTIC CONVERTER, REMOVING AND INSTALLING .

Vehicle with 2.5L FSI:

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-- Loosen the hose clamps -2 and 3- and remove the air duct hose.

-- Loosen the hose clamps -1 and 2-.

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-- Press the release buttons on both sides and disconnect the hose -3- for the crankcase ventilation at the air duct pipe.

-- Remove the bolt -arrow- and the air duct pipe.

Heat shield with catch:

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Not all models have the heat shield.

-- Release the retainer -arrow-, pull the heat shield -1- off to the left and remove it.

Heat shield with threaded connection:

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Not all models have the heat shield.

-- Remove the nut -1- and remove the bracket with the lock washer -3-.

-- Remove the heat shield -2-.

Vehicle with 2.0L TFSI:

-- Remove the drive axle heat shield. Refer to DRIVE AXLE HEAT SHIELD, REMOVING AND INSTALLING .

-- Remove the Oxygen Sensor 1 before Catalytic Converter -GX10-. Refer to HEATED OXYGEN SENSOR, REMOVING AND INSTALLING .

-- Remove the bolt -1- and free up the pressure pipe.

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-- Remove the bolt -1- and the screw-type clamp.

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-- Loosen the bolt -2- and push the catalytic converter to the side.

-- Remove the bolts -arrows- and nuts -1- and remove the heat shield.

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-- Disconnect the connector -1-.

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-- Remove the bolts -arrows- and move the Particulate Filter Differential Pressure Sensor -G1037- with the bracket to the side.

Continuation for All Vehicles:

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-- Unclip the wiring guide.

-- Press the locking mechanism downward -arrow A-.

-- Release the connector -arrow B-.

-- Remove the connector -1-.

Make sure that no brake fluid enters the control module connector housing. This could lead to contact corrosion and thereby cause the system to fail.
A contaminated housing must be carefully cleaned with compressed air.

-- To protect against escaping brake fluid, place enough lint-free cloths in the area below the hydraulic control unit.

-- Mark the brake lines on the hydraulic control module.

Fig 1: Brake Line Tightening Sequence