Height Sensor, where is it?

[rowanmoor]

I keep getting faults for the height sensor. It only take 1 or 2 trips after clearing the faults before it is back again.

I noticed this as mine seems to be staying in hard mode (electrically) far more than it should. i.e. driving along the motorway in a straight line on cruise and it is switching in and out of hard mode. Whether the sensor is the cause or not I don't know. It could just be that the uneven M23 by Gatwick happens to give an oscillation that causes it to think I am driving across a field.

So, does anyone know... Where exactly is the sensor? Is it easy to get to? Where are the connectors between it and the ECU to try cleaning as a start?

[jorgy9]

Hi there

hopefully sounds like a dry solder point on its PCB or a bad contant. This is just an infrared optical sensor so doesn't really "break". That's the height sensor, located somewhere at the rear of the front subframe, connected to the antiroll bar:




the innards:




To start with you might want to simply check continuity from its plug to the ECU. Look page 45 to 47 of the manual posted here for info on operational voltage, pins, etc. :

http://club-xm.com/forum/index.php?showtopic=3068

As far as I remember pin number are printed on the ECU plugs in tiiiiny characters.

cheers
George

[wirdy]

Under the car looking towards the front, find the front centre sphere then track right following the main spar of the front subframe until you find it attached to a bracket and linked to the suspension with a small plastic link rod with wobble joints. You may find the link rod has come off, they're quite flimsy.

You can unbolt the height sensor and move it around carefully (to check if it moves freely) without disconnecting the plastic link as I had to do this when adjusting my steering rack damper on numerous occasions whilst trying to get it perfect.

[rowanmoor]

Thanks, one day I will get under there and check it over and check the connections.

I had noticed the document in that thread. I have been trying to work out what it classifies as a fault. Presumably a signal that does not make sense given the offset of the 2 sensors. So, a dodgy connection so that the signals are intermittent is a good bet. Can it get crud in there to block the gaps between the teeth in the ring?

[Peter.N.]

Just above the o/s end of the steering rack. I had to take mine off to get to the pipes.

Peter.N.