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Removing and Installing Main Wiring Harness - Engine Compartment



Removing And Installing Main Wiring Harness - Engine Compartment

Information







NOTE:
- The repair instructions document "Removing and installing main wire harness" is divided into several chapters because of its size.
- For body repairs, refer to the specific chapters on installing and removing individual sections of wiring.

ATTENTION:
- 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 lines are damaged, isolate them (disconnect, remove plug contacts from plug connections etc.) and replace the original wire harness by installing new lines.

Removing main wiring harness - engine compartment

Removing main wiring harness - engine compartment on left
Remove left front wheel housing liner.
Remove left front main headlight.
Remove front apron.

1. Push in latch -b- on connector for sensor -a- until it is felt to engage -Arrow A-.







2. Release locking mechanism latch -b--Arrow B- and pull connector off the sensor -a--Arrow C-.
3. Remove line together with lock carrier support -Arrow D-.
4. Turn bulb holder (wheel housing) slightly and remove -Arrow A-.







Only for vehicles with tyre pressure monitoring system.

5. Release connector on antenna for tyre pressure monitoring system (wheel housing) -Arrow B- and disconnect it -Arrow C-
6. Release central connector for additional heating -Arrow A- and remove -Arrow B-.







7. Release connector on lateral acceleration sensor (wheel housing) -Arrow A- and remove -Arrow B-.







8. Open clip -Arrow C- and remove line -Arrow D-.

Only in cars with additional heating

9. Release connector on circulating pump -Arrow E- and pull it off -Arrow F-.
10. Open clip -Arrow G- and remove line -Arrow G-.
11. Release plug connection for ABS sensor and brake pad wear indicator (wheel housing) -Arrow A- and disconnect it -Arrow B-.







12. Open clips -Arrow C- and remove line -Arrow D-.

Only for vehicles with automatic headlight levelling system.







13. Release connector on angle sensor (rear wheel suspension)-Arrows A- and remove -Arrow B-.
14. Release connector (front cross member) -Arrow A- and pull it off -Arrow B-.







15. Unclip socket -Arrow C-.
16. Unscrew fastening nut and remove ground straps together with twist lock from threaded bolt -Arrow D-.
17. Release connector on air flow sensor -Arrow A- and pull it off -Arrow B-.







18. Open clips -Arrow C- and remove line -Arrow D-.
19. Open clips (on radiator) -Arrows A- and remove line -Arrows B-.







20. Release the two connectors -Arrows C- and remove them -Arrows D-.
21. Unscrew fastening nut -1- (front side member) and remove ground straps together with twist lock -a- from threaded bolt -Arrow E-.
22. Remove air cleaner housing.
23. Release connector on headlight housing -Arrow A- and pull it off -Arrow B-.







24. Open clips -Arrows C- and remove line -Arrows D-.
25. Cut tie-wrap (upper side member) -A-.







26. Release clips -Arrows B-, open them -Arrows C- and remove line -Arrow D-.
27. Open clips -Arrows E- and remove line -Arrow F-.
28. Open upper cover of external power connection -Arrow A-.







29. Undo fastening nut -2- and remove line -Arrow B-.
30. Open lower cover -Arrow C-.
31. Undo fastening nut -3- and remove line -Arrow D-.
32. Remove relay carrier in plenum panel E-Box.
33. Release connector on alarm siren -Arrows A- and pull it off -Arrow B-.







34. Open clips -Arrows C- and remove line -Arrows D-.
35. Unscrew fastening nut -1- (next to relay carrier in plenum panel E-Box) and remove ground straps together with twist lock -Arrow A-.







36. Press out rubber sleeve (firewall) -Arrow B- and remove line inwards.

Remove main wire harness - dashboard area and centre console.

Removing main wiring harness - engine compartment in centre
Remove wiper motor.
Remove left and rear engine compartment covers.
Remove plenum panel at front left.

1. Unscrew fastening nut -1- (firewall centre) and remove ground strap together with twist lock -a--Arrow A-.







2. Open clip -Arrow B- and remove line -Arrow C-.
3. Release connector on brake booster using a suitable aid (e. g. an angled piece of wire) -a--Arrow A- and pull it off -Arrow B-.







4. Release connector on distance sensor (brake assist system) using a suitable aid (e. g. an angled piece of wire) -a--Arrow A- and pull it off -Arrow B-.







5. Release connector on distance sensor (brake assist system) using a suitable aid (e. g. an angled piece of wire) -a--Arrow A- and pull it off -Arrow B-.







6. Release connector on brake fluid reservoir -Arrow A- and pull it off -Arrow B-.







7. Open clips -Arrows A- and remove line -Arrow B-.







8. Open clip (brake assist system) -Arrows C- and remove line -Arrow D-.
9. Open clip (firewall) -Arrow A- and remove line -Arrow B-.







10. Press out the rubber sleeve (firewall) to the inside -Arrows C-.

Remove main wire harness - dashboard area and centre console.

Removing main wiring harness - engine compartment on right
Remove right front wheel housing liner.
Remove right front main headlight.

1. Push in latch -b- on connector for sensor -a- until it is felt to engage -Arrow A-.







2. Release locking mechanism latch -b--Arrow B- and pull connector off the sensor -a--Arrow C-.
3. Remove line together with lock carrier support -Arrow D-.
4. Turn bulb holder (wheel housing) slightly and remove -Arrow A-.







Only for vehicles with tyre pressure monitoring system

5. Release connector on antenna for tyre pressure monitoring system -Arrow B- and pull it off -Arrow C-.
Remove front apron.

6. Release plug connection to front apron -Arrow A- and disconnect -Arrow B-.







7. Unscrew fastening nut -1- (front side member wheel housing) and remove ground straps together with twist lock -a--Arrow C-.
8. Open clip -Arrow D- and remove line -Arrow E-.
9. Release connector on headlight housing -Arrow A- and pull it off -Arrow B-.







10. Open clips -Arrows C- and remove line -Arrows D-.

Only for vehicles with automatic headlight levelling system.







11. Release connector on angle sensor (rear wheel suspension)-Arrows A- and remove -Arrow B-.
12. Remove plug connection on washer-fluid reservoir from bracket -Arrow A-.







13. Release plug connection -Arrow B- and disconnect it -Arrows C-.
14. Release connector on lateral acceleration sensor (wheel housing) -Arrow A- and remove -Arrow B-.







15. Open clip -Arrow C- and remove line -Arrow D-.
16. Release plug connection for ABS sensor and brake pad wear indicator (wheel housing) -Arrow A- and disconnect it -Arrow B-.







17. Open clips -Arrow C- and remove line -Arrow D-.
18. Release connector on air flow sensor -Arrow A- and pull it off -Arrow B-.







19. Open clips -Arrow C- and remove line -Arrow D-.
20. Remove air cleaner housing.
21. Remove filler neck from reservoir for windscreen washer system.







22. Release connector on coolant reservoir -Arrow A- and pull it off -Arrow B-.
23. Remove right front main headlight.
24. Open clips (upper side member) -Arrow A- and remove lines -Arrow B-.







25. Remove plenum panel at front right.
26. Remove DME control module.
27. Unscrew fastening nuts -1- (to rear of DME control module) and remove ground straps together with twist lock -a--arrows-.







28. Release plug connection (to right of DME control module) -Arrow A- and remove it to the front -Arrow B-.







29. Release plug connection -Arrow C- and disconnect -Arrow D-.
30. Open clip (holder for DME control module) -Arrow A- and remove line -Arrow B-.







31. Unscrew fastening screw -2- and fastening nuts -3- and remove DME control module -Arrow C-.
32. Open the holders in the passenger compartment -Arrows A-.







33. Undo fastening nuts -4- and remove air intake housing -Arrow B-.
34. Remove coolant reservoir.
35. Release clip (ABS hydraulic unit) -Arrow A-, open it -Arrow Band remove the line -Arrow C-.







36. Remove rubber sleeve -Arrow D-.
37. Remove line from rubber sleeve -Arrow E-.
38. Unclip the line -arrow-.







39. Release connector -Arrow A- and disconnect it from the ABS hydraulic unit -Arrow B-.







40. Release clips -Arrow C-, open them -Arrow D- and remove line -Arrow E-.
41. Press out rubber sleeve -Arrow F- and remove line from the passenger compartment.

Remove main wire harness - dashboard area and centre console