E39 ASC and ABS Lights on

Day off on Friday, out in the car, start up normal.  I turn the ignition on and let all the warning lights go out before starting engine.  All lights go out.

Drove 1/4 mile ASC and ABS light come on. Drove to where I was going, switched off and then came back 30 mins later.  Re-start car and ASC and ABS lights stay on and don't clear at all.  Drive car forward about 10mon and and lights go off. Great.  Drive 1/4 to 1/2 mile and both lights then come back onand then stay on for the rest of the trip.

Having closely followed Killian's and Tom's woes about the ASC light being stuck on, I checked the ASC throttle actuator cable and it is fine but in both Killian's and Tom's cars it is only the ASC light that is on. 

Can I presume that I have a different fault then?

Can I assume that it is a dodgy wheel sensor then? 

Cruise still works fine, but the gear changes are maybe a bit out compared to recently, this would also suggest a wheel sensor.

Do I need to jack up all four corners and measure the resistance of each sensor in an effort to find the dodgy one, or do I stop being tight fisted and having the attitude 'I'll fix it myself' and take it to a garage for a diagnostic check?

Any suggestions for having both ASC and ABS lights on?

Andrew

Thanks Tom, much appreciated.

Andrew

http://bimmer.roadfly.com/bmw/forums/e39/6261321-1.html

Is your speedo still working as normal?

I'd say wheel sensor. If your cruise is still working it's unlikely to be the off side rear. Rumour is the near side rear is linked to the speedo so if thats still working that one should still be okay. However if your gearchanges are out then maybe it detects engine speed to road speed and therefore it'll change at different times??

Fronts? I'm not sure as I would have thought that as the ASC is affected then it would be a rear one as it needs to detect a spinning driven wheel.

When both my lights came up my cruise packed in also and that was definately the right rear (off side).

Good luck with this. I spent a weekend trying to id which sensor. it's quiker to take it to the dealer for a diagnostics check. You don't have to have the work done, just id the fault.

Something a garage did for me when testing to see if it was sensors or the ABS Unit (unfortunately ended up being the unit) is to swap them round... Front and Rears are different, but if you swapped the rears over and your speedo stops working then you know it is that one (Speedo definately works off the near side rear).

In the 6 months i have had mine I have had all 4 sensors replaced and the ABS Control Unit  but at least I know they will all be ok for a bit!

Good luck this weekend, and just be careful in taking them out as they can break...

Andrew Rolland wrote: Thanks Whitey How did you detect what was the problem?  Did you take it to a dealer for a diagnostic check? Just foned my local garage (Not BMW), they say they should be able to diagnose it and tell me what is wrong with it. I quite fancy checking it myself though, I wonder if the long haired general will let me get my socket set out this weekend instead of looking at wedding photographers?????? Andrew

Hi Andrew. I am on very good terms with my main dealer due to me not only having had all my 5's serviced there for the past 10 years but also parting with fortunes in the parts depatment for the e30!!!

Like I say I'd spent a day just messing about and it was mid winter (as cold as it is at the moment). In the end I popped in on the off chance to see if they were busy. Although snowed under (between xmas and the new year) with flat batteries etc. my preffered service adviser asked me for my keys, invited me to help myself to a coffee, whizzed it round the back and returned it litterally 10 mins later, handed me back the keys and said "right rear". I asked him how much I owed him, he just stated "have a happy new year mr. white" and the matter was closed.

You see he knows i know a bit and that he won't get the additional work out of me (over and above the service to get the stamp and the strictly main dealer stuff) due to me having the tools and facilities at home to complete the work. He also realises that a good will gesture and politeness means more to me than any other part of their service.

I walked into the parts dept and bought one there and then, went home fitted it and hey presto.......a clear dash.

Good luck but I fear you'd be quicker to just run it into the dealer and get them to diagnose it. Tell them your sure it's a wheel sensor, just which one?

Trevor

Andrew Rolland wrote: PS Any chance you could take my E39 to your dealer then Whitey????

Seriously though, all dealers have a duty to diagnose the problem. You are not bound over to have the work done. It would only be their minimum charge and I'm yet to speak to anyone who has successfully diagnosed which one it is without the daignostics kit.

However if your local garage can help, I bet he'd be cheaper.

I am lucky though, to have (to a certain extent) straightened the dealer out. I know that when it comes out from the service, all the advisories will need doing. The guy knows that I will take the car away and deal with them myself so he's not gonna gain at all, except maybe on the parts. 

Andrew, here are the few pages from the Bentley manual.  The pictures didn't scan in great because I just used the B&W setting, but if you're stuck for one, let me know and I'll scan it in on better quality.

There is another section on the ABS/traction control hydraulic unit, removing & installing

If you want that also, let me know

http://img.photobucket.com/albums/v333/tosullivan/Car/Bentle y340-4.jpg

http://img.photobucket.com/albums/v333/tosullivan/Car/Bentle y340-27.jpg

http://img.photobucket.com/albums/v333/tosullivan/Car/Bentle y340-26.jpg

http://img.photobucket.com/albums/v333/tosullivan/Car/Bentle y300-14.jpg

http://img.photobucket.com/albums/v333/tosullivan/Car/Bentle y300-13.jpg

http://img.photobucket.com/albums/v333/tosullivan/Car/Bentle y300-12.jpg

Latest on my problem.

Start car, lights stay on then disappear after driving forward about 10 m.  I get to the end of my street and brake (20 mph max speed) at the give way and the ABS kicks in.

This happens every time I touch the brake pedal until I get above 25-30mph when both warning lights come back on.  At least I know the ABS unit isn't broken, it just can't tell when a wheel is or isn't about to lock. 

So it must be a wheel sensor!

Tranny is also playing up.  No warning lights or anything but it won't change from 2nd to 3rd (which is about the same speed 25-30 mph when the lights come back on) half the time and also changing from 3rd to 4th is a problem sometimes.  ECU obviously can't tell what speed the car is doing in relation to the tranny output sensor.  Hopefully this tranny fault is related!

Car is booked in to local garage for a diagnostic at 08.10 on Thursday morning.  Get the check done then off to work a bit late.  Get the sensor on Thursday lunchtime and fit on Saturday.

Andrew