Removing and installing ABS control unit J104/ABS hydraulic unit N55, vehicles with 4-cyl. diesel engine with diesel particulate filter — VW

📋 Procedure

1. Use to read code of ABS control unit J104 and note it.
2. Disconnect battery Electrical system27Battery; Disconnecting and reconnecting battery.
3. Remove engine cover 10Engine cover; Removing and installing engine cover.
4. Remove underbody panelling on right General Body Repairs - Exterior66Underbody panelling; Assembly overview - underbody panelling
5. Remove diesel particulate filter 26Emission control; Assembly overview - emission control.

6. Unbolt right drive shaft from flange, lower it and secure it Running gear, axles, steering40Drive shaft; Removing and installing drive shaft.
7. Remove nuts (1).
8. Remove nuts (2) and take out bracket for particulate filter (3).
9. Swivel particulate filter downwards and place on subframe.
10. Seal openings with sealing plug set for engineVAS 6122. [Note: Particulate filter does not have to be removed from the vehicle.]
11. Lower particulate filter until it lies on the steering mechanism. [Note: When lowering, be careful with the cables of the exhaust gas temperature sender and the Lambda probe to avoid damage.]
12. If fitted, unscrew nut (1) and remove heat shield (2).
13. Unlock connector from ABS control unit J104 in (direction of arrow) and pull it off.
14. Apply brake pedal depressorV.A.G 1869/2.
15. Connect hose of bleeder bottle (1) to bleeder valve of front left brake caliper.
16. Open bleeder valve.
17. Connect hose of bleeder bottle (1) to bleeder valve of rear left brake caliper.
18. Open bleeder valve.
19. Depress brake pedal at least 60 mm using brake pedal depressorV.A.G 1869/2.
20. Close front left and rear left bleeder valves.
21. Place sufficiently lint-free cloths under ABS control unit J104 and ABS hydraulic unit N55. [Note: Ensure no brake fluid gets onto contacts.]
22. First, mark the two brake lines (A) and (B) coming from brake master cylinder.
23. Detach brake lines from ABS hydraulic unit N55.
24. Seal brake lines and threaded holes immediately using sealing plugs1H0 698 311 A or sealing plugs5Q0 698 311.
25. Mark and unscrew brake lines (1) to (4).
26. Seal brake lines and threaded holes immediately using sealing plugs1H0 698 311 A or sealing plugs5Q0 698 311.
27. Turn hexagon fitting bolt out of retainer (arrow).
28. Pull ABS hydraulic unit N55 together with ABS control unit J104 and side bracket out of rubber dampers of bracket in (direction of arrow).
29. Turn ABS hydraulic unit N55 with ABS control unit J104 on its head.
30. Unbolt bracket from ABS hydraulic unit N55 in engine compartment and remove.
31. Remove ABS hydraulic unit N55 together with ABS control unit J104. [Note: Remove sealing plugs from new hydraulic unit only when the corresponding brake line is to be fitted.If sealing plugs are removed too early from the hydraulic unit, brake fluid can escape, and it can then no longer be guaranteed that the unit can be sufficiently filled and bled.When installing the hydraulic unit, ensure that rubber dampers are not pressed out of bracket.]
32. Before installing holder of ABS hydraulic unit N55 on bracket, spray rubber dampers with silicone lubricantD 007 000 A2.
33. Using assembly toolV.A.G 1410/8, carefully fit brake lines. [Note: Replace seals, self-locking nuts and the clamp for particulate filter.Re-fit cable ties and electric wires in the same place.Adhere to the correct installation sequence 26Emission control; Assembly overview - emission control.]
34. Align exhaust system stress-free 26Exhaust pipes/silencers; Align exhaust system stress-free.
35. Connect battery Electrical system27Battery; Disconnecting and connecting battery.
36. Remove brake pedal depressorV.A.G 1869/2.
37. Bleed hydraulic system .
38. Code control unit J104 with in "Guided Fault Finding".

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