’97 E39 touring 523se abs and asc saga

Hey folks.

I have just registered with the forum but I have looked at past posts regarding my abs light problem and you have been a great help so far.

The problem I hope you can help me with is (here goes!!)

The abs and asc lights came on intermittantly with the usual turn ignition off and then restart car ad lights would go off 10 yards down the road.  This started happening more frequently until it was happening all the time.  The front passenger wheel bearing then started growling at me so got that changed but since then the abs/asc lights stayed on all the time apart from a couple of times the lights would go off but I would hear the abs pump or electric motor whirring and also when dabbing the brake pedal I would be getting the abs vibration through it as well.  Very soon after the 2 lights would come on and all the whirring and brake pedal vibrations stopped. obviously the abs system was then disabled.  I changed the wheel sensor on the same corner as I thought the dodgy bearing had knackered the sensor.  Since changing the sensor the lights have gone out (YEHA) but I am still getting the whirring from the abs unit and the pedal is still having arguments with me.

There, I think thats all the detail

I really hope someone can help

Oops nearly forgot, below 20-25 mph all whe pupming stops.

I need to update this now.  Just travelled about 4 miles (2nd journey since changing sensor) and the abs would whirr now and again but as I was getting home it kept whirring and then lights came on

I also noticed that in drive rather than semi auto it wouldnt change out of gear, until i put it back into steptronic

PLease Please help me

Many Thanks

Denis

Cheers Andrew

I have the car booked in for a diagnostics on wednesday, so will get the low down then.  I did try taking a chance by changing the sensor as I thought it was a bit of a coincidence that the abs knackered up the same time as the bearing.  What I have found though is that the tranny only started playing up when I changd the sensor.  Could I have got a duff sensor?

Hi

Thats a very interesting point about the tyre tread. I changed the front tyre because the faulty bearing wore the outside of the tyre so its like an egg!

So there is a difference with treads.  will put original wheel back on and see if that cures it.

Thanks for the help.  Will let you know how I get on on wednesday

Andrew Rolland wrote: Yes, if you have worn front tyres compared to your rears and one front tyre more worn than t'other then this too will upset the ABS system as wheels will be rotating at different speeds and it doesn't like it.  This confuses the autobox also and it has been known to force it into limp mode. Andrew

Its the ASC system who have trouble with differnet tyretread in front and also get gearshifting problem sometimes also it gets to limpmode, but more normal is that is dont go up to 4 and 5 gear and no varninglights at all.

The limit 5% is smaller in curves becuse the system must compensate fore the differance rotationspeed.

To much differnet front axel and rear axel could also give problem with ASC regulation. also to much differnace in tyrepressuare.

En E60 and up, the RDC system take signal from wheelsensors instead of sensors in each wheel.