Removing Main Wire Harness

Removing And Installing Main Wire Harness

Tools







Technical values







Preliminary work

1. Remove battery.
2. Remove plenum panel cover.
3. Remove CD changer.
4. Remove navigation unit with retaining bracket.
5. Remove loudspeaker amplifier.
6. Remove trim panels for front luggage compartment.
7. Remove front-end control unit.
8. Remove front wheel housing liner on left and right.
9. Remove front cover.
10. Remove tank for windscreen washer system.
11. Remove rear luggage-compartment lining.
12. Remove relay carrier.
13. Remove rear wheel housing liner.
14. Remove left and right side trim panels.
15. Remove dashboard.
16. Remove heating/fresh-air unit.
17. Remove front seat at left and right.
18. Remove left and right scuff plate.
19. Loosen fuse box.
20. Remove B+ line from power distributor to engine connection point.
21. Remove relay carrier 1.
22. Remove vehicle electrical system control unit.
23. Remove operator control unit for garage door opener.
24. Remove front roof lining.

Removing main wire harness

CAUTION:
Damage caused by improper handling of main wire harness
- The main wire harness contains all airbag lines, antenna lines and optical waveguides.
- The main wire harness must therefore not be cut for major repair work and must be replaced complete.
- If individual wires are damaged, these must be "shut down" (disconnect wires, remove plug-in contacts from plug connections, etc.) and replaced by installing new wires. Lay the new wires along the main wire harness and tie them to it.

INFORMATION: Depending on the equipment I No., the installation positions of the audio components in the front luggage compartment differ.












1. Disconnect plug connection between main wire harness and front end wire harness, right -1-.
1.1. Release plug connection between front-end wire harness and main wire harness, right -Arrow a- and disconnect -Arrow B-.
1.2. Turn socket 90° clockwise and remove.







2. Pull off connector on fuse box for fan -2-.
2.1. Unclip fuse box for fan -Arrow A- and lift up and off -Arrow B-
2.2. Release lid -arrows- and open -Arrow C-.
2.3. Pull off connector on fuse box for fan -Arrow D-.







3. Loosen ground point left -11-.
3.1. Screw off fastening nut and remove ground straps.

4. Release plug connection between main wire harness and front-end wire harness, left -12- and disconnect. Unclip connector socket.
5. Release connector on hydraulic unit -13- and pull it off.
6. Release connector on brake fluid sender -14- and pull it off.
7. Release connector for tire pressure monitoring system control unit -15- and pull it off.







8. Unclip wire harness for front end control unit -arrow-.







9. Unclip wire harness to loudspeaker amplifier -Arrows A- and remove adhesive tape -Arrow B-.







10. Unclip wire harness to CD changer/navigation unit -arrows-.
11. Remove grommets -16- left and right.
12. Pull through main wire harness in direction of plenum panel.
13. Disconnect and release ABS wire harness front left and right -17 and 18-.
13.1. Release and disconnect plug connection for wheel sensor at left and right.
13.2. Unscrew fastening screw of connector socket.
13.3. Release rear wire harness.

14. Release and pull off connectors on front antenna for tire pressure monitoring system -19 and 20- at left and right.
15. Release and pull off connector of switching element for filler flap -21-.
16. Pull off connector from tank filler neck -22-.

INFORMATION: Only in the cabriolet.

17. Release connector on rod antenna -23- and pull it off.







18. Unclip wire harness on end plate under windscreen at the three retaining clips -arrow-.
19. Release connector on GPS antenna -24- and pull it off.
20. Release connector on radio antenna -25- and pull it off.
21. Release connector for vertical sensor -26- and pull it off.
22. Release connector for pressure switch -27- and pull it off.

INFORMATION: Only for vehicles with I number 536.

23. Release connector for alarm siren -28- and pull it off.
24. Release and pull off B+ line -29- from power distributor.







25. Release plug connections for PASM, front left and right -30 and 31- -Arrow a- and disconnect.
26. Release and pull off connectors for windscreen washer system spray nozzle, left and right -32 and 33-.

INFORMATION: Only for vehicles with TPM.

27. Release and pull off connector on front angle sensor for headlight beam adjustment -34-.
28. Release and pull off connector on wiper motor -38-.
29. Release and pull off connector on alarm horn -39-.







30. Undo the four fastening nuts on the battery retaining bracket and remove the battery retaining bracket.







31. Release connector on fuel level sender -40- -Arrow A- and pull it off -Arrow B-.







32. Unclip wire harness on end plate under windscreen at the two retaining clips -arrow-.
33. Remove grommets -41- in centre, and on left and right.
34. Pull through main wire harness in direction of interior.

Exposing main wire harness in passenger compartment







1. Loosen seat belt mount at left and right.
1.1. Press off cap -1- with a screwdriver and unscrew the fastening screw -2-. Remove seat belt with fitting -3- and spacer sleeve -4-.

2. Disengage floor covering at the support and lay it in the vehicle interior.







3. Remove left and right support.
3.1. Unlock locating peg -1- of the support using the commercially available removal tool Disassembly tool, universal NR.21.







3.2. Unscrew fastening screws -2- and nuts -3- and carefully pull the support up and out of the retaining points.

Removing main wire harness in passenger compartment















1. Disconnect plug connections for main wire harness to rear wire harness -33 and 34-.
1.1. Release plug connections for main wire harness to rear wire harness -arrows A- and disconnect.







2. Disconnect plug connections for main wire harness to engine wire harness -35 and 36-.
2.1. Release plug connections for main wire harness to engine wire harness -arrows A- and disconnect -arrows B-.
2.2. Release sockets for main wire harness -arrows C- and push down from relay carrier -arrows D-

3. Release connector for rear vertical sensor -37- and pull it off.
4. Release and pull off connector on DME control module -38 and 39-.







5. Loosen ground point in luggage compartment -40-.
5.1. Screw off fastening nut and remove ground strap.

6. Release and pull off connector on rear angle sensor for headlight beam adjustment -41-.
7. Remove rubber sleeves -42-.







8. Disconnect main wire harness plug connections for rear lid wire harness -47 and 48-.
8.1. Release main wire harness plug connections for rear lid wire harness -arrows A- and -arrows B- disconnect.
8.2. Release connector sockets for main wire harness -arrows C- and push down from retaining clip -arrows D-.
8.3. Unclip tie-wrap -arrow E-.







9. Disconnect PASM plug connections -49 and 50- at left and right.
9.1. Release and disconnect plug connection for wheel sensor at left and right -arrow a-.

10. Release and pull off connector on rear antenna for tire pressure monitoring system -51 and 52- at left and right.
11. Disconnect and expose ABS wire harness rear on left and right -53 and 54-.
11.1. Release and disconnect plug connection for wheel sensor at left and right.
11.2. Unscrew fastening screw of connector socket.
11.3. Release rear wire harness.







12. Unclip the main wire harness in the area of the rear left spring strut.
13. Pull off connector on front seat-belt tensioner -56 and 57- at left and right.







14. Unclip main wire harness to the left side wall.
14.1. Unclip main wire harness to the left side wall -arrow A-.
14.2. Unclip cable duct to the left side wall -arrow B-.







15. Loosen cable duct to the left side wall.
15.1. Unclip main wire harness to the bottom of the B-pillar -arrow A-.
15.2. Take out cable duct upwards out of the rear wall plate -arrow B-.

16. Release and pull off connector for airbag sensor, centre left and right -58 and 59-.
17. Release and pull off connector for ParkAssist control unit -60 and 61-.
18. Release and pull off connector for rear end convenience systems control unit -62 to 64-.







19. Loosen ground point under the driver's seat -65-.
19.1. Screw off fastening nut and remove ground straps.







20. Unclip ground point under driver's seat.
21. Release and remove connectors for telephone control unit -66 to 69-.







21.1. Unclip wire harness for telephone control unit.







22. Loosen ground point under the passenger's seat -70-.
22.1. Screw off fastening nut and remove ground straps.







23. Unclip wire harness at door sill.
24. Disconnect the plug connection between main wire harness and wire harness for door, left and right -75 and 76-.
25. Release and pull off connector for gateway control unit -81-.
26. Release and pull off connectors for KESSY/PAS control unit -82 and 83-.
27. Release and pull off connector for stop light switch -84-.
28. Release and pull off connector for pedal sensor -85-.







29. Loosen ground point under the unit carrier -92-.
29.1. Screw off fastening nut and remove ground straps.

30. Release and pull off connector for tilt sensor control unit -93-.







31. Disconnect plug connections between main wire harness and wire harness for heater/air-conditioning unit -95 and 96-.
31.1. Release lower plug connection on heater/air-conditioning unit -arrows a- and unplug.







31.2. Release upper plug connection on heater/air-conditioning unit -arrows a- and unplug.







31.3. Cut tie-wraps (main wire harness to heater/air-conditioning unit wire harness) with side cutters. Remove main wire harness.

32. Release and disconnect plug connection for rain sensor -99-.







33. Disconnect plug connection of make-up mirror, left and right -100 and 101-.
33.1. Unclip plug connection from console -arrow B-.
33.2. Release plug connection -arrow a- and disconnect it -arrows C-.







34. Unclip cable duct at front of roof frame.







35. Unclip main wire harness at front of roof frame.







36. Remove main wire harness from A-pillar -area A-.
37. Pull off connector for antenna amplifier, left and right -102 to 106-.







38. Loosen ground points on dashboard bracket.
38.1. Unscrew fastening nuts and remove ground straps.







39. Unclip length compensation at the steering column.
39.1. Remove expansion rivet and length compensation.







40. Unclip cable guide on dashboard bracket.







41. Loosen holder for relay carrier.
41.1. Unscrew the two fastening screws and remove the relay carrier holder from the dashboard bracket.







42. Loosen main wire harness at left dashboard bracket.
42.1. Screw off fastening nut and remove fastening screw.
42.2. Unclip main wire harness on cable guide.







43. Loosen main wire harness at right dashboard bracket.
43.1. Unclip main wire harness on both cable guides.







44. Loosen main wire harness at centre dashboard bracket.
44.1. Undo the four tie-wraps and remove main wire harness.