Part 1
WM 970919 Removing and installing main wire harness
Tools
Technical values
Preliminary work
1. Remove battery. -> 270619 Removing and installing battery - section on "Removing" 27061900 Removing and installing battery
2. Remove plenum panel cover. -> 852219 Removing and installing cover - section on "Removing" 85221900 Removing and installing cover
3. Remove CD changer. -> 916019 Removing and installing CD changer - section on "Removing" Service and Repair
4. Remove navigation unit with retaining bracket. -> 911219 Removing and installing navigation unit - section on "Removing"
5. Remove loudspeaker amplifier. -> 914419 Removing and installing loudspeaker amplifier - section on "Removing"
6. Remove luggage compartment trim panels -> 700519 Removing and installing trim panel for front luggage compartment - section on "Removing"
7. Remove front-end control unit. -> 944919 Removing and installing front-end control unit - section on "Removing" 94491900 Removing and installing front control unit
8. Remove front wheel housing liner on left and right. -> 505619 Removing and installing front wheel housing liner - section on "Removing" Service and Repair
9. Remove front cover. -> 519219 Removing and installing front cover - section on "Removing" 519219 Removing and installing Cover For Front Underbody
10. Remove tank for windscreen washer system. -> 926019 Removing and installing tank for windscreen washer system - section on "Removing" Service and Repair
11. Remove dashboard. -> 701819 Removing and installing dashboard - section on "Removing" 701819 Removing and installing instrument panel
12. Remove heating/fresh-air unit. -> 851519 Removing and installing heating/fresh-air unit - section on "Removing" Service and Repair
13. Remove front seat at left and right. -> 720119 Removing and installing front seat - section on "Removing" 720119 Removing and installing front seat
14. Remove left and right scuff plate. -> 680519 Removing and installing inner door sill trim - section on "Removing"
15. Remove rear side trim panel at left and right. -> 707519 Removing and installing rear side trim panel - section on "Removing" 707519 Removing and installing rear side trim panel
16. Loosen fuse box. -> 978409 Loosening and securing fuse box - section on "Loosening" 97840900 Undoing and securing fusebox
17. Remove B+ line from power distributor to transmission connection point. -> 974519 Installing and removing wire harness for starter battery - section on "Removing" 974519 Removing and installing wire harness for battery wiring
18. Remove relay carrier 1. -> 978319 Removing and installing relay carrier 1 - section on "Removing" 97831900 Removing and installing relay carrier 1
19. Remove vehicle electrical system control unit. -> 971019 Removing and installing vehicle electrical system control unit - section on "Removing" Service and Repair
20. Remove operator control unit for garage door opener. -> 967819 Removing and installing operator control unit for garage door opener - section on "Removing" 96781900 Removing and installing control unit for garage door opener
21. Remove sunroof motor. -> 601419 Removing and installing sunroof motor - section on "Removing"
22. Loosen front headliner in windscreen area. -> 708419 Removing and installing headliner - section on "Removing"
Information
Only in the cabriolet.
23. Remove front headliner. -> 708319 Removing and installing front headliner - section on "Removing" 708319 Removing and installing front roof trim panel
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.
Overview of connectors for front main wire harness, shown on the 911
1. Disconnect plug connection between main wire harness and front-end wire harness, right -1-.
Disconnecting plug connection between front-end wire harness and main wire harness, right
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-.
Pulling off connector on fuse box for fan
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-.
Loosening ground point
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. -> 453019 Removing and installing hydraulic unit - section on "Removing" Service and Repair
6. Release connector on brake fluid sender -14- and pull it off.
7. Release connector for tyre pressure monitoring system control unit -15- and pull it off. -> 443419 Removing and installing control unit for tyre pressure monitoring system - section on "Removing" Service and Repair
8. Unclip wire harness for front end control unit -arrow-.
Unclipping wire harness
9. Unclip wire harness to loudspeaker amplifier -Arrows A- and remove adhesive tape -Arrow B-.
Unclipping wire harness to loudspeaker amplifier
10. Unclip wire harness to CD changer/navigation unit -arrows-.
Unclipping wire harness to CD changer/navigation unit
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-. -> 976555 Replacing ABS wire harness - section on "Removing" 976555 Replacing wire harness for anti-lock brake system (ABS)
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 tyre pressure monitoring system -19 and 20- at left and right. -> 443819 Removing and installing antenna for tyre pressure monitoring system - section on "Removing" Service and Repair
15. Release and pull off connector of switching element for filler flap -21-. -> 553819 Removing and installing switching element for filler flap - section on "Removing" Service and Repair
16. Pull off connector from tank filler neck -22-. -> 200719 Removing and installing filler neck - section on "Removing"
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-.
Unclipping wire harness
19. Release connector on GPS antenna -24- and pull it off. -> 911319 Removing and installing GPS antenna - section on "Removing" Service and Repair
20. Release connector on radio antenna -25- and pull it off. -> 914719 Removing and installing radio antenna - section on "Removing" Service and Repair
21. Release connector for vertical sensor -26- and pull it off.
22. Release connector for pressure switch -27- and pull it off. -> 878319 Removing and installing pressure switch - section on "Removing" Service and Repair
Information
Only for vehicles with I number 536
23. Release connector for alarm siren -28- and pull it off. -> 966519 Removing and installing alarm siren - section on "Removing" Service and Repair
24. Release and pull off B+ line -29- from power distributor. -> 978919 Removing and installing power distributor - section on "Removing" 97891900 Removing and installing power distributor
25. Release plug connections for PASM, front left and right -30 and 31- -Arrow a- and disconnect.
Disconnecting PASM plug connection