4-Cylinder Diesel Engine
ABS Control Module and ABS 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)
• Heated oxygen sensor wrench (3337)
• Wrench SW 13 (T10384)
• Assembly tool (T10365)
• Transport Protection (T10404)
• Engine bung set (VAS 6122)
• Plug (1H0 698 311 A)
• Install the transportation protection after removing the ABS hydraulic unit (N55).
• The warranty on the ABS hydraulic unit will not be honored if there is no transportation protection.
1 Transport protection for valve domes (foam)
2 Sealing plugs M10
3 Sealing plugs M12
Removing
Component location: The ABS control module (J104) is attached to the ABS hydraulic unit and is located inside the engine compartment on the right side.
1. ABS hydraulic unit with ABS control module
2. Brake booster with tandem master cylinder
Do not bend the brake lines near the ABS hydraulic unit!
- Get the coding from the ABS control module and write it down.
Use the vehicle diagnostic tester.
• Chassis
• Brake System
• Anti-lock braking system ABS/EDS/ASR/ESP Mark 60 EC
• Function
• Check coding in the ABS control module J104
• Disconnect battery ground strap for all further work. See if a coded radio is installed. Get the anti-theft code beforehand, if necessary.
Danger of causing damage to electronic components when disconnecting the battery.
• Complete the steps for disconnecting the battery.
- Disconnect the battery.
- Remove the engine cover.
The engine cover bracket on the cylinder head cover can break if it is removed incorrectly. Always remove the engine cover according to the following procedure.
- Pull the engine cover - arrows - upward out of the fasteners in the given sequence.
- Reach under the engine cover as far as possible.
- Remove the nuts - arrows - and the heat shield - 1 - from the diesel particulate filter.
- Remove the toothed belt guard and the clips - arrows -.
- Unclip the lines from the cover.
- Remove the noise insulation or impact guard.
• Reducing agent can irritate skin, eyes and lungs.
• If reducing agent gets on your skin, rinse the skin with water.
• Seek medical attention if necessary.
Protect any electric connect from coming contact with reducing agent using a plastic bag and cable ties. Reducing agent can cause damage to the electric connections when it crystallizes.
Seal off all openings on the lines and connections immediately with suitable plugs to prevent dirt from getting in. Even the smallest piece of dirt can cause considerable damage to the system.
Do not allow reducing agent to get on clothing or on the vehicle body parts.
If this happens, rinse off the reducing agent with clear water and then dry with a lint-free cotton cloth.
Use warm water and a sponge if the reducing agents has already crystallized.
Reducing agent that has not been removed will crystallize after awhile and will cause damage.
- Disconnect the connector - 4 - from the reducing agent injector (N474) - 2 -.
• Do not open the clamp - 1 - on the reducing agent injector.
- Release the retainer - 3 - in - direction of arrow 1 -.
- Remove the coupling in - direction of arrow 2 - without using any tools and without jerking.
- Remove the tunnel bridge.
- Remove the clamping sleeve - 1 -.
- Remove the right underbody trim.
- Remove the NOx sensor 2 control module (J881).
- Loosen the nuts - arrows - and remove the exhaust pipe - 1 -.
- Remove the bracket bolts - arrows -.
- Remove the exhaust pipe together with the reducing agent injector, the NOx sensor control module 2 and the exhaust door control unit (J883).
- Release and remove connectors - 1 - through - 3 -.
- Guide the wires out.
- Remove the particulate filter bracket bolt - 1 -.
- Raise the vehicle.
- Loosen and remove the turbocharger/particulate filter clamp - 1 -.
• The illustration shows the clamp screw - 1 - from underneath. In some cases, this can be installed from the top.
- Disconnect the connector - 2 - from the differential pressure sensor (G505).
- Remove the bolt - 4 -.
- Remove bolt - 3 -.
- Remove the differential pressure sensor and move it to the side.
- Free up the diesel lines from the bracket for the differential pressure sensor.
- Remove the bolts - 1 -.
• Lower the differential pressure sensor and the bracket.
- Remove the screws - arrows -.
- Release and disconnect the connector - 3 -.
- Remove the exhaust pressure sensor 1 (G450) - 1 - from the bracket - 2 -.
- Remove the bracket - 2 -.
- Loosen the clamp and remove the hoses - 4 - from exhaust pressure sensor 1 - 1 -.
- Remove the nut - arrow - and the bracket - 1 - on top of the cylinder head.
- Disconnect the connector from the exhaust gas temperature sensor wiring harness in - direction of arrow -.
- Disconnect the exhaust gas temperature sensor - arrow -.
- Remove the exhaust gas temperature sensor.
Danger of causing damage to the de-coupling element.
- Secure the de-coupling element with (T10404) - arrow -.
- Remove the clamp - 2 - from the EGR pipe - 1 -.
- Remove the bolts - 1 - and remove the drive axle cover - 2 -.
- Unbolt the right drive axle from the flange, lay it down and secure it.
- Remove nuts - 1 -.
- Remove the nuts - 2 - and remove the particulate filter bracket - 3 -.
- Move the particulate filter downward and lay it on the subframe.
- Seal off all openings with (VAS 6122).
• Do not remove the particulate filter from the vehicle.
- 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 sensor 1 and the heated oxygen sensor to prevent damage.
- Remove the nuts - 1 - and remove the heat shield - 2 -, if equipped.
- Disconnect the connector from the ABS control module - in direction of arrow -.
- Insert (V.A.G 1869/2).
- Attach the bleeder bottle bleed hose - 1 - to the left front brake caliper bleed valve.
- Open the bleed valve.
- Attach the bleeder bottle bleed hose - 1 - to the left rear brake caliper bleed valve.
- Open the bleed valve.
- Depress the brake pedal at least 60 mm with the (V.A.G 1869/2).
- Close left front and left rear bleeder valves.
Do not remove (V.A.G 1869/2).
- Place a lint-free cloth under the ABS control module and the ABS hydraulic unit.
Make sure no brake fluid gets onto contacts.
- First mark both brake lines - A - and - B - on the master cylinder and then remove them from the ABS hydraulic unit.
- Seal brake lines and threaded holes with sealing plugs (1H0 698 311 A).
- Mark brake lines - 1 - through - 4 - and then remove them.
- Seal brake lines and threaded holes with sealing plugs (1H0 698 311 A).
- Remove the hex bolt form the bracket - arrow -.
- Remove the ABS hydraulic unit with the ABS control module and the bracket sideways in - direction of arrow - from the rubber bushings on the console.
- Turn the ABS hydraulic unit with the ABS control module upside down.
- Remove the bracket from the ABS hydraulic unit inside the engine compartment.
- Remove ABS hydraulic unit with ABS control module.
Installing
Install in reverse order of removal. Note the following:
• Remove the plugs on the new ABS hydraulic unit only when installing the brake line.
• Brake fluid will leak out if the plugs are removed too early from the ABS hydraulic unit. The system will then not have sufficient brake fluid and will not adequately bled.
When installing the mount, make sure the rubber insulation does not push out of the bracket. Make sure the ABS hydraulic unit is secure after installing it otherwise malfunctions can occur.
• Replace the seals, self-locking nuts and the particulate filter clamp.
• Reinstall the cable ties and wires back in their original location.
• Pay attention to the installation sequence.
Installation Sequence
- Align the exhaust system without tension.
- Make sure the rubber buffers fit correctly in the mounts when installing the engine cover.
Before installing the engine cover, make sure the 4 mounting elements (ball sockets) are correctly positioned; adjust them if necessary. Otherwise the engine cover will get damaged.
- Connect the battery.
- Remove (V.A.G 1869/2).
- Bleed hydraulic system. Refer to => [ Hydraulic System, Bleeding ] Service and Repair.
Perform a basic setting on the steering angle sensor (G85) , the transverse acceleration sensor (G200) and the brake pressure sensor (G201) after installing the ABS control module and the ABS hydraulic unit.
Use the vehicle diagnostic tester.
• Chassis
• Brake System
• Anti-lock braking system ABS/EDS/ASR/ESP Mark 60 EC
• Function
• Sensor basic setting (G85/ G200/ G201/ G251)
If a new ABS control module was installed, it must be coded.
Use the vehicle diagnostic tester.
• Chassis
• Brake System
• Anti-lock braking system ABS/EDS/ASR/ESP Mark 60 EC
• Function
• ABS Control Module J104, coding
Tightening Specification
