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

WARNING: This page is about a different car, the 2024 Audi S6 and 2024 Audi A6 Quattro. However, it is still accessible from the selected car via links, so may be relevant.

-- If replacing the control module, select the "Replace control module" program using the Vehicle Diagnostic Tester Refer to DIAGNOSTIC ENTRIES .

-- Follow the instructions in the Vehicle Diagnostic Tester display.

-- Insert the Brake Pedal Actuator:V.A.G 1869/2 between the brake pedal and driver seat. Press the brake pedal down at least 60 mm.

Fig 1: Identifying Brake Pedal Actuator

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By doing this, the valves in the brake master cylinder are closed and the brake fluid reservoir does not run empty.

CAUTION:

Leaking brake fluid increases the risk of injury.

Risk of skin irritation and injury.

- Wear safety gloves.

Depending on the wheel combination, remove the wheels. Refer to WHEELS AND TIRES .

Fig 2: Identifying Protective Cap, Bleed Screw And Container Bleeder Hose
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-- Remove the protective cap -3- from the bleed screw -1- on a front brake caliper.

-- Connect the bleeder bottle hose -2-.

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

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

-- Repeat the procedure on a rear brake caliper.

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

-- Remove the engine control module.

Vehicles with diesel engine. Refer to ENGINE/MOTOR CONTROL MODULE -J623-, REMOVING AND INSTALLING
Vehicles with gasoline engine. Refer to ENGINE/MOTOR CONTROL MODULE -J623-, REMOVING AND INSTALLING

-- If installed, remove the connectors -3 and 4- from the bracket and free up the wire.

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-- Free up the wiring harness -1-.

-- Remove the bolts -arrows- and then remove the bracket -2- for the engine/motor control module.

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

Fig 3: Hand Tightening Union Bolts

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-- Mark the brake lines for reinstallation.

-- Remove the brake lines -1 and 2- from the ABS Hydraulic Unit -N55- and free up if required.

CAUTION:

Risk of destroying the brake lines by bending.

- Never change the shape of the brake lines.

-- Seal brake lines and threaded holes with clean sealing plugs.

TIP:

Make sure that no brake fluid enters the control module connector housing.

-- Release the connector -3- and disconnect from the control module.

-- Free up the wires.

-- Remove the hydraulic control unit -1- carefully from the pins -arrows-.

Fig 4: Identifying ABS Control Module with ABS Hydraulic Unit Removal

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-- Remove the bolt -arrow- and the bracket -1-.

Fig 5: Identifying The Control Module Removable Bolt And Bracket

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