Abs sensors on e39 5 series

Hi all.
Recently I had the misfortune to have my abs warning light and traction control light come on, along with the speedo not working! I took the car to my local garage and had a diognostic check done on it, this revealed that there is a sensor problem at the o/s rear wheel. I changed the sensor and the warning lights went out and the speedo started working temporarily, before the warning lights came back on. This afternoon, I have stripped out the rear hub assembly only to find that there seems to be nothing visibally wrong!

My questions are; Could the problem be the reluctor ring......and if so, why? Or is the new sensor faulty?
Any advice or suggestions will be gratefully recieved as it's not much fun driving through a 30mph limit with a police car up my ass and my speedo not working!

Answers on a postcard please to.....lol

Mick

Hi mate,


It is not unheard of "new" speed sensors packing up soon after replacement.

I would take it back to the garage that fixed the problem initially, it should be covered under warranty.

The sensor wires are surprisingly easily damaged if not handled with care whilst removing/installing.

Spartan wrote:Hi mate,


It is not unheard of "new" speed sensors packing up soon after replacement.

I would take it back to the garage that fixed the problem initially, it should be covered under warranty.

The sensor wires are surprisingly easily damaged if not handled with care whilst removing/installing.

Hi Spartan.

I did the work myself

Mick

Ah!

Ok.


Was it an original sensor?

Before you go and replace anything- I would go and get the codes read again mate.

........just in case.

Hi Spartan

It was a spurious sensor that i used. The codes were read before commencement of work this afternoon and pointed to the issue that i have.

By the way, thanks very much for getting back to me so promptly!

Mick

Ok, I would put it down to a dudd sensor and get it replaced by the vendor and then see how you go...........I would als double check the car end of the sensor wires for any obvious damage.

We have seen this a few times where new ABS sensors have failed almost instantly after installation, sometimes it is down to a cheap part but sometimes it has been down to "rough" handling of the sensor whilst installing.

I'm more likely to err on the dud sensor too, I was told to handle with care and I did. The trouble is, you don't know how carefully the pickers and packers handle things like these. Is there a way of testing the sensor?
How bad would the reluctor ring need to be before it threw a fault code?

Mick

To be honest mate, there is no real way of testing the sensor.

Reluctor ring? honestly, never had to replace one on a beemer yet.

My money would be on a sensor, do you have a code reader of your own mate?

My mate has the code reader, it's a good quality `Snap-on` one

Today I fitted another new wheel speed sensor and that still never cured it so I thought I'd replace the reluctor ring. After a reasonably easy strip down I replaced the reluctor ring and re-assembled the whole thing, all to no avail as the abs and traction control lights are still on and the speedo is still not bloody working!!!!!!!!!!!!!!!

Mick

Hmmm, despite what you have tryed, it still seems like the speed sensor to me.... But maybe its the connector or the wire itself... id get hold of a multimeter and test the wire/connector.. it may be damaged or the connector maybe damaged... It seems odd, that when you changed it previously, the speedo worked then stopped again... now after changing it again you are getting total failure.... it seems unreasonable to suspect another failure, but not to be ruled out unfortunately...

hmmm, just give the wires a check mick, and let us know, so we can look into it further....

Thanks.
Mightybmw....

Hi Mighty.

The speedo works until the abs/tc warning lights come on, then the needle falls to zero. Wether it's reading the correct speed at this time, remains to be seen.
Like you've just advised, I think it's a wire checking process next!

Best regards
Mick

Ok mick, do let us know how you get on...

Will do mate

hi mate ive got the exact same problem as u, when the car heats up after about 10 mins my speedo stops working the mpg guage stops working,abs light and esp light comes on , plugged in diagnostics equipment and it said speed sensor on n/s/r wheel, changed it and problem is still there,

Right guys!

After replacing all four wheel speed sensors (some of them twice!), Both back wheel bearing assemblies (Because they are complete with reluctor rings!), had the abs pump checked (it came back with no faults found!) I finally thought `sod this` and ended up taking it to the local garage! The very friendly mechanic checked it out with his "Wireless" BMW diagnostic kit and found that there is another ABS gismo behind the glove box, this was removed and sent for repair. £50.00 later, my car was back on the road with no abs or traction control lights on and all systems functioning normally. If only I'd have taken it there when the warning lights came on!!!!!!!!!!

From this episode I've learnt to pay someone with the right gear to do the job, as you can soon run up a few hundred quid and be in the same shit!

Best regards
Mick