motor on rear suspension

[potter]

just had car in for m.o.t. 2002 s3 BAM. just need new c.v. boots as they have rubbed through. But he said there is some sort of motor on/near the rear suspension that seemed to have a lot of play in it, but to be honest he had no idea wot it was. I not had a look myself but will be getting it up for a look soon, just wondered if anyone has any ideas to wot it could be, cheers

 

[s3ollie]

its probably one of the sensors for headlight levelling. you have one on the front also

 

[simch]

The headlight levelling is on the front, the sensor on the back suspension arm is the ESP sensor, there is a drop link arrangement, I think only on one of the rear arms that feeds info to the ECu for the ESP. Maybe both sides its been ages since i was under there!

 

[s3ollie]

i have the sensor on the rear tie bar but i dont have ESP

 

[claudefrog]

the sensor on the rear is for the headlight self leveling. it failed on mine and the self leveling went funny, replaced it and fixed the headlights

 

[s3ollie]

AFAIK the ESP uses a longitudinal and lat sensor behind the steering column or glove box depending on year and the signals from the ABS sensors on each hub

 

[S3Steve]

The headlight levelling is on the front, the sensor on the back suspension arm is the ESP sensor, there is a drop link arrangement, I think only on one of the rear arms that feeds info to the ECu for the ESP. Maybe both sides its been ages since i was under there!

The front and rear sensors are both for the headlight self levelling, the system takes a signal from both to determine wether the car is pitched nose up or down and levels the headlights to suit. It would be unable to tell how the car is pitched from one sensor.