Electronic Brake Control Module: Service and Repair
ABS 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)
Sealing Plug Repair Kit, Part No. 1H0 698 311 A
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 the left of the engine compartment under the battery carrier.
Do not bend the brake lines near the hydraulic unit.
- Read and note the present control module coding.
- On vehicles with a coded radio, note the code. Retrieve it if necessary.
- Disconnect battery.
- Remove the intake hose, air filter and battery.
- Remove the battery carrier.
- Open the cable channel, remove both wiring harnesses and lay them aside.
- Remove the cable channel from the console.
- Press the red securing clip down in direction of - arrow -.
- Release and remove connector from control module in direction of - arrow -.
- Insert (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 the brake master cylinder and remove them.
- Plug the brake lines and threaded holes immediately with sealing plugs from the repair kit Part No. 1H0 698 311 A.
- Mark, unfasten and plug the remaining brake lines (brake calipers).
- Lift the hydraulic unit with control module up and out of the dampers - arrow -.
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 and unit may not be sufficiently filled or adequately bled.
• When installing the hydraulic unit, make sure the damper rubber is not pushed out of the bracket. The damper rubber must lie on the longitudinal member cover plate.
- Installation is in reverse order of removal.
Fastening Sequence of Brake Lines
- Remove (V.A.G 1869/2).
- Bleed brake system. Refer to => [ Brake System, Bleeding ] Brake System, Bleeding.
- Enter radio code.
- Code the ABS control module (J104) in guided fault finding.
A steering angle sensor (G85), transverse acceleration sensor (G200), longitudinal acceleration sensor (G251) and brake pressure sensor 1 (G201) basic setting must be done.
