Control Module and Hydraulic Unit
Control Module and Hydraulic Unit
Special tools, testers and auxiliary items required
• Torque wrench (V.A.G 1331)
• Torque wrench (V.A.G 1410)
• Brake pedal actuator (V.A.G 1869/2)
Plug (1H0 698 311 A)
After separating the control module from the hydraulic unit, always install transport protection on the hydraulic unit for the valve domes.
Warranties will not be granted for hydraulic units without transport protection.
1 Transport protection for valve domes (foam)
2 Sealing plug M 10
3 Sealing plug M 12
Removing
Component location:
The control module is bolted to the hydraulic unit and is located at right in the engine compartment.
Do not bend the brake lines near the hydraulic unit.
- Read and note the present control module coding.
- Disconnect the battery.
- Remove engine cover.
1.9L Diesel Engine:
- Disconnect connection hose to intake connection.
- Remove intake flap motor.
2.0L Diesel Engine:
- Remove connecting pipe between intake hose and turbocharger.
- Remove upper part of toothed belt cover.
Diesel Engines with Particulate Filter:
- Disconnect the connector for the Exhaust Gas Temperature (EGT) Sensor 4 (G648) - 2 - and Heated Oxygen Sensor (HO2S) (G39) - 3 -.
- Unclip the Exhaust Gas Temperature (EGT) Sensor 4 (G648) and Heated Oxygen Sensor (HO2S) (G39) cables from the brackets on the plenum chamber and engine.
- Disconnect the connector - 1 - on the Exhaust Pressure Sensor 1 (G450).
- Remove the bolt - 2 - and then remove the bracket - 3 - together with the Exhaust Pressure Sensor 1 (G450) in - direction of arrow -.
- Move the bracket - 3 - and exhaust pressure sensor 1 forward.
- Remove engine cover.
- Remove the particulate filter bracket bolt - 1 -.
- Raise vehicle.
- Loosen and remove the turbocharger/particulate filter clamp - 1 -.
• The illustration shows the clamp bolt - 1 - from underneath. In some cases, this can be installed from the top.
- Remove exhaust system bracket from subframe - arrows -.
- Remove the bolts - 1 - and remove the drive axle cover - 2 -.
- Disconnect the right drive axle from the flange, lay it down and secure it.
- Loosen the double clamp on the exhaust pipe and push it toward the rear.
- Remove the nuts - 1 - and lower the particulate filter.
- Remove the nuts - 2 - and remove the particulate filter bracket - 3 -.
- Lower the particulate filter just enough so that it touches the steering gear.
• While lowering the particulate filter, pay close attention to the cable, the Exhaust Gas Temperature (EGT) Sensor 4 (G648) and the Heated Oxygen Sensor (HO2S) (G39) to prevent damage.
- Lower vehicle.
Continuation for All Vehicles
- Remove the nuts - 1 - and remove the heat shield - 2 - if equipped.
- Release and remove connector from control module in - direction of arrow -.
- Install (V.A.G 1869/2).
- Attach bleeder hose of bleeder bottles to left-front and left-rear brake caliper bleeder valves and open bleeder valves.
- Operate brake pedal using (V.A.G 1869/2) at least 60 mm.
- Close left front and left rear bleeder valves.
- Do not remove (V.A.G 1869/2).
- Place sufficient lint-free cloths under the control module and hydraulic unit.
Make sure that brake fluid does not come in contact with the terminals.
- First, mark both brake lines from master cylinder - A and B - and remove from the hydraulic unit.
- Seal brake lines and threaded holes with Sealing plugs (1H0 698 311 A).
- Mark brake lines (brake caliper) - 1 - to - 4 - and remove.
- Seal brake lines and threaded holes with (1H0 698 311 A).
- Remove the hex bolt form the bracket - arrow -.
- Remove the hydraulic unit, the control module and the side retainer in - direction of arrow - from the bracket rubber insulation and turn it on its head.
- Remove the retainer from the hydraulic unit in the engine compartment.
- Remove the hydraulic unit and the control module.
Removing the Control Module from Hydraulic Unit
- Set hydraulic unit with control module upward onto a clean, level surface.
- Remove the inner Torx bolt from the control module.
- Pull control module off from hydraulic unit - arrow - without angling.
- Carefully pull off all sealing rings from valve domes of hydraulic unit.
• On a disconnected control module, circuit board is laid open.
• No moisture or particles of dirt must penetrate in interior of control module.
• Avoid build-up of static electricity!
- Cover control module magnetic coils with a lint free cloth.
After separating the control module and hydraulic unit, use transport protection for valve body.
Installing the New Control Module
Excessive shaking (e.g. dropping, impact) may destroy the control module. Control module must then no longer be used.
• Surface must be cleaned before assembling.
- Slide all sealing rings - A - slightly over the valve dome.
- Place control module without canting it onto hydraulic unit.
Sealing rings are then brought into their end position.
- Install the hydraulic unit and control module with the new inner Torx bolts diagonally according to the tightening specification.
• A new control module may be installed a max. of two times to a used hydraulic unit, to ensure that the elastic gasket seals sufficiently.
• A control module which was once in driving operation must not be installed a second time.
Installing
• Do not remove sealing plugs at new hydraulic unit until the corresponding brake line is about to be installed.
• If the sealing plugs are removed too early, brake fluid can escape. If this occurs, unit may not be sufficiently filled or adequately bled.
- Installation is performed in the reverse order of removal.
When installing the mount, make sure the rubber insulation does not push out of the bracket. After installing, make sure the hydraulic unit and the control module are secure, otherwise malfunctions will register.
- Remove (V.A.G 1869/2).
- Bleed brake system. Refer to => [ Brake System, Bleeding with Brake Filler/Bleeder Unit VAS 5234 or VAG 1869 ] Brake System, Bleeding with Brake Filler/Bleeder Unit VAS 5234 or VAG 1869.
- Code the ABS Control Module (J104) with the "Guided Fault Finding".
A Steering Angle Sensor (G85), Transverse Acceleration Sensor (G200) and Brake Pressure Sensor 1 (G201) basic setting must be done.
Tightening Specifications
