ABS System Components on Front Axle, Removing and Installing

ABS system components on front axle, removing and installing

Note:
^ Removing and installing ABS system components is identical for FS III and FN 3 brake calipers.





1 - / Left Front ABS Wheel Speed Sensor G47/ Right Front ABS Wheel Speed Sensor G45
^ Before inserting sensor, clean mounting hole inner surface and coat with lubricating paste G 000 650

2 - Wheel bearing housing
3 - Hex socket head bolt, 8 Nm
4 - Splash plate
5 - Hex bolt, 10 Nm
6 - Wheel bearing
^ Renew each time after removing

7 - Phillips-head screw
8 - Brake disc
9 - Wheel hub with rotor
10 - Circlip

Removing and installing wheel speed sensor on front axle

Removing

- Raise vehicle.





- Raise vehicle.
- Disconnect speed sensor and speed sensor wiring connector - 1 -.
- Remove bolt - 2 - from wheel bearing housing.
- Disconnect ABS wheel speed sensor from wheel bearing housing.

Installing
- Before inserting wheel speed sensor, clean hole inner surface and coat speed sensor with lubricating paste G 000 650.
- Insert speed sensor into hole in wheel bearing housing and tighten bolt to 8 Nm.
- Connect wheel speed sensor to speed sensor wiring.
- Turn wheels fully to left and right hand lock and check clearance to speed sensor wiring.

Checking rotor on front axle
- Raise vehicle.
- Remove wheel.
- Rotate brake disc to check that the rotor is not damaged or dirty.
- If rotor is damaged, remove wheel hub with rotor and replace.

Checking rotor lateral run-out
- Raise vehicle.
- Remove wheel.





- Turn wheel hub and check gap between rotor and speed sensor dimension - a - is even.
Dimension - a - = 0.3 mm
- If rotor is damaged, remove wheel hub with rotor and replace.

Front wheel speed sensor wiring, removing and installing

Special tools, testers and auxiliary items required




^ Wiring harness repair kit VAS 1978

Removing
- Obtain radio code on vehicles with coded radio.
- Disconnect battery.





- Disconnect intake hose - 1 - and connectors - 2 - from Mass Air Flow (MAF) sensor.
- Remove bolts - 3 - , - 4 - and - 5-.
- Remove air cleaner completely.





- Release control module connector - arrow 1 - and pull it off - arrow 2 -.





- Release multi-pin connector cover cap with a screwdriver and remove.





- Release secondary locking device (violet) in direction of - arrow - with a small screwdriver.





ABS Mark 20 IE 25-pin connector T25
Contact assignment of 25-pin connector T25 wiring harness/ ABS control module J104.





ABS/EDL/ASR/ESP Mark 20 IE 47-pin connector T47
Contact assignment of 25-pin connector T47 wiring harness/ ABS control module J104.





ABS/EDL/ASR/ESP Mark 60 47-pin connector T47
Contact assignment of 25-pin connector T47 wiring harness/ ABS control module J104.





- Push out relevant contacts using an ejection tool from wiring harness repair set VAS 1978.
- Separate connector from wheel speed sensor and wheel speed sensor wiring.





- In addition, disconnect connection - 1 - on vehicles with a brake pad wear indicator. Unclip wiring from retainer - 2 -.
- Remove faulty wheel speed sensor wiring.

Installing
- Route new wheel speed sensor wiring.
- Connect wheel speed sensor to wheel speed sensor wiring.





- Clip in wheel speed sensor wiring - arrows -.
Make sure the wiring is not twisted when installing the wheel speed sensor wiring in the wheel housing.
- Insert brake pad wear indicator connector into retainer on suspension strut.
- Guide contact into connector housing.





- Push individual wiring seals in up to limit stop with an insertion tool from VAS1978.
- Secure contacts with secondary locking device and install multi-pin connector cover cap.