E39 Brake/ABS Light

Hi,
A couple months ago I took the car (2000 528i) for inspection to a local, non-BMW shop. It passed and I picked up the car at the end of the day. As
soon as I started it the BRAKE/ABS light on the dash came on. It comes on and goes off. It's very intermittant.
I called the shop the next morning asking if they accidentally might have disconnected something by mistake, but as you can guess they completely washed their hands of any wrongdoing.'
Well the light continues to come on and off, and it's mostly on, and I believe the ABS does not function.
Any ideas?
Jeff
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Dodgey ABS sensor at a wheel? In the inspection they're supposed to check over everything.
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You are describing the symptoms of a bad wheel speed sensor.
I doubt that the service activity and the sensor problem are related. Having said that, there is a way that the ABS valve body can generate an error that will turn the light on. If this is the problem, the light will come on after the car is started, but before you begnin moving, or it might come on after using the brakes. The Speed Sensor related failure will come on for no apparent reason as you are driving down the road. The Speed Sensor error will clear itself when the car is shut off and restarted, but my recollection is that the valve body error will set and remain -- I'm a bit fuzzy on that detail though.
You are correct, the ABS system is not functioning when the light is ON. If the light is not on, the ABS should function normally.

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My problem sounds very close to what you are describing. Is this the sensor as described in the other reponse to my question? If not, is this expensive to fix?
Please advise Jeff
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Speed sensors on my E36 run to about $100 each. It is expensive to buy enough to do the car when only one of them is needed.
I'm a wee bit confused though, I described two conditions. Which do you have?
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sensors on my E36 run to about $100 each. It is expensive to buy

..but do they often actually go bad or is cleaning all that's necessary? The old diff speed sensors used to fail quite frequently but it was usually the connectors rather than the sensor itself.
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>Speed

On my first E36, I could not correct the malfunction by cleaning them.
I don't know the incidence of failure vs. getting dirty. I'd always try cleaning the metal dust off of them, and cleaning the connectors first, but my limited experience is that if there is an error, it takes replacment to correct.
The diagnostic port will tell you what the problem really is.
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Howdy --
My 99' 528i is having intermittemnt issues with the ABS. The ABS light is on contiuously, I replaced the wheel sensors in the rear, about 80 bucks apiece.... no biggy. I have reset the comp a few times during maintenance, however the light stays on solid. The speedo jumps from zero to normal speeds every once in a while, (I could drive for a few hundred miles then the speedo works again), and of course the light is on always. It's a stupid design to incorporate speedo mileage indicator ABS system having multiple things into what could be a very pricing perportioning value.
I have contacted a few wrecking yards, one needs to be aware of the correct serial number sequence I think they mentioned "001" as the key indicator when purchasing the correct replacement. I think they mentioned 99' and 00' used the same block and sending device. Then they changed it again in 01' going forward.
I heard they're rebuild units for a few hundred bucks, but that could be a hit and miss issue. The wrecking yards charge 450 bucks for the unit and you can get a shop to swap it out and bleed the system and resync it for around 100 addition dollars.
What a pain in the ass for a known auto maker such as BMW to design and continue to support this type of lousey system. ABS or not it is lousey.
BTW -- new uninstalled part BMW is asking around 1500.00....
Sorry for the rant..... just had to make point

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