Thread: Air susp inactive/ Hdc inac and then some....

Leaving a clients house about two weeks ago I noticed the ride height was locked and then consequently the hdc and air suspension inactive notifications on the display along with the other warning lights associated with this fault

Over the past two weeks it sometimes comes on and then goes away once I drive a couple of meters

About two days ago I pulled out of a carpark onto a main road and the car aggressively stopped itself, I absolutely **** myself and thought I had blown the transmission. It felt like the abs kicked in and perhaps the engine power dropped also and all this happened at about 15/20 kph at my best recollection, It came to a complete stop then I slowly drove off fine

Today I noticed that the warnings would only come up when I turned a corner

Anyway I have pulled the abs/ wheel speed sensors and they appear to look ok and I cleaned them ( I realize they may well be shot even thou they look ok)... I checked the wiring.... ok

I checked my battery voltage which was at 12.42, and when engine running with headlights on high beam I got 13.8 which quickly rose to 14+ so I don't think its a low voltage thing but I will still check all earth points etc

I have read that the ignition barrel can play up and not provide enough voltage to components beyond it?, I also read the steering angle sensor can give these problems?

What I cant understand is why the air suspension would have anything to do with the abs/hdc/ dsc system but ill look at some diagrams now.... perhaps they share the same earth or something, anyway at this stage I think ill replace all the wheel sensors if they are not too dear

Would anyone have any input as to how the system works or that has had similar problems.. I've read a heap of threads but not really any where the brakes applied themselves


03TD6



Dave

Thanks mate,

I had the front two out and cleaned them but no difference (the fault is constantly active at all times now)

I will do a resistance and voltage test on them all and inspect the rear ones also as soon as I have the time to do so, I wouldn't mind betting they are cheaper from bmw or there may even be an aftermarket alternative



Dave