abs light

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325nut
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Sun Feb 26, 2006 10:48 am

i have had an ongoing problem with abs light on dash. it comes on when ign is turned on and stays on ! i had a broken sensor wire which it failed mot on, i replaced it and light is still on ! checked resistance of sensors and they range from .952 to .975 is this correct and is the problem likely to be one or both of the relays ? please help ! doing my head right in now !
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Brianmoooore
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Sun Feb 26, 2006 11:00 am

Your sensor resistance readings are in the right sort of area.
If you are saying that your ABS light comes on with the ignition and stays on when you start the engine, then I have read that the problem is with one of the ABS relays.
You don't mean it comes on with ignition, goes out with engine start, then comes on again when you move, do you?
Unfortunately, I've never had to deal with this particular ABS fault, so I can't give any advice based on experience, although there is one outside waiting for me now! Don't know when I'll get to sorting it though.
M5pilot
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Sun Feb 26, 2006 11:21 am

Fixed this exact problem on a car 2 weeks ago.

It turned out to be the ABS relay as stated above.

Its under the glove box and very easy to change. I think it costs about Ԛ£25 +VAT from the dealers.

If you dont want to splash out come down to a meet and Im sure someone will be willing to take one out of their car and try it on yours.
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Brianmoooore
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Wed Mar 01, 2006 2:37 pm

M5pilot wrote:Fixed this exact problem on a car 2 weeks ago.

It turned out to be the ABS relay as stated above.

Its under the glove box and very easy to change. I think it costs about Ԛ£25 +VAT from the dealers.

If you dont want to splash out come down to a meet and Im sure someone will be willing to take one out of their car and try it on yours.
What relay is this? I've about ten E30s here, about half of them with ABS, and the only relay under/behind the glovebox is the one for the windows/roof with the door open.
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Brianmoooore
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Wed Mar 01, 2006 2:45 pm

Brianmoooore wrote:, although there is one outside waiting for me now! Don't know when I'll get to sorting it though.
Had a look at this one now. First thing I discovered was that the fault doen't always happen, especially immediately after starting, but does happen without the car moving.
There are two relays under the plastic cover on the ABS pump. One is just an ordinary relay, but rated at 50A and with round pins. The other is the same, but has a diode in it as well.
Couldn't see anything obviously wrong with either relay when I opened them up, but the fault appears to have gone after changing the one with the diode, although the car has only run for about 10 minutes and travelled a couple of hundred yards since.
Rich25i
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Wed Mar 01, 2006 6:33 pm

hi dont know if this will help but check the plugs under the rear seat (black
on my coupe). mine kept doing this when i got mine. one was badly cracked replaced it all was well after.
just a thought

RICH
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Brianmoooore
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Wed Mar 01, 2006 7:19 pm

Rich25i wrote:hi dont know if this will help but check the plugs under the rear seat (black
on my coupe). mine kept doing this when i got mine. one was badly cracked replaced it all was well after.
just a thoughRICH
Sensor related faults, like this, only throw the fault light when the car actually moves.
JAMZ
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Wed Mar 01, 2006 7:30 pm

Ive got the same problem on the CAB, lights allways on from the moment i turn the igniton and stays on..yet my ABS is working ok as far as i know,,tried to get the wheels to lock up but find it very difficult even in the wet so somethings working...

the relay controll unit is behind the glovebox Brainmoore..if thats what yer on about,i swapped these over and didnt make a difference unless the one that i got was knackered too..

the lil black connectors under the rear seats on mine are ok,not cracked so im not sure where my problems lies
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Brianmoooore
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Wed Mar 01, 2006 7:49 pm

JAMZ wrote:Ive got the same problem on the CAB, lights allways on from the moment i turn the igniton and stays on..yet my ABS is working ok as far as i know,,tried to get the wheels to lock up but find it very difficult even in the wet so somethings working...

the relay controll unit is behind the glovebox Brainmoore..if thats what yer on about,i swapped these over and didnt make a difference unless the one that i got was knackered too..

the lil black connectors under the rear seats on mine are ok,not cracked so im not sure where my problems lies
I've never come across an E30 with any ABS related relays any where near the glovebox. The ABS ECU is above the glovebox, but no relays.
The relays I've referred to are under the black plastic cover (remove one obvious screw and pull off) on the ABS pump behind the LH headlamps.
JAMZ
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Wed Mar 01, 2006 10:39 pm

Oops.. Sry Brianmoore.. yea the ECU is above the glove..my bad..

Funny i had that cover off the outher day to check the relays and saw nothing obvious..any way of checking those relays(voltmeter) or anything.. outher than changing them over for known working ones,id like to know if that was the cause... though like i said as far as im aware the ABS is working

my bulbs been taking out right now as its dam anoying

rgds
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Brianmoooore
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Wed Mar 01, 2006 11:25 pm

The ABS light can be turned on directly by the ABS ECU from pin 29, or by the relay with the diode being unenergised. This is the relay I changed on mine, but since the fault was sometimes intermittant and I haven't run the car for more than ten minutes since, I'm not sure the fault has gone away.
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Brianmoooore
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Wed Mar 01, 2006 11:30 pm

Missing bulb or bulb that doesn't go out when it should is an MOT failure, so you need to sort it.
aus325
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Thu Mar 02, 2006 8:57 am

I'm another chasing this same fault (light permanently on from turn of key).
I'll be checking relays when I get a chance, interesting to note that that an underdash relay is mentioned here... :

http://www.bmwe30.net/cgi-bin/datacgi/d ... Section=06
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Brianmoooore
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Thu Mar 02, 2006 9:27 am

aus325 wrote:I'm another chasing this same fault (light permanently on from turn of key).
I'll be checking relays when I get a chance, interesting to note that that an underdash relay is mentioned here... :

http://www.bmwe30.net/cgi-bin/datacgi/d ... Section=06
Could possibly be on an early car. I only deal with post '88 stuff. If anyone knows, please tell me!
ac
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Thu Apr 27, 2006 8:07 pm

Brianmoooore

I'm having the same problem but sensor resistance readings are between 1000 - 1400 are these right.

Thanks

Ac
Sooty
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Thu Apr 27, 2006 8:45 pm

Brian.

I'm in the process of retrofitting ABS into my cab (don't ask me why....it seemed like a good idea at the time :roll: )

Anyway, the complete donor loom, etc came from a late 89' 325i .

The picture below shows the ABS ECU. The 5 pin socket sitting on top of it is part of the ABS loom and is for the much discussed relay that hides in the glove box.

Image

I'm genuinely surprised that you have'nt come across one before. :o
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Brianmoooore
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Thu Apr 27, 2006 9:52 pm

Sooty wrote:Brian.

I'm in the process of retrofitting ABS into my cab (don't ask me why....it seemed like a good idea at the time :roll: )

Anyway, the complete donor loom, etc came from a late 89' 325i .

The picture below shows the ABS ECU. The 5 pin socket sitting on top of it is part of the ABS loom and is for the much discussed relay that hides in the glove box.

Image

I'm genuinely surprised that you have'nt come across one before. :o
Still say I can't remember seeing this relay on any E30. Definitely not on two that are stripped out now, and not shown on my wiring diagrams.
What colours are the wires to the relay?
Sooty
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Thu Apr 27, 2006 10:33 pm

Could'nt see any pin numbers on the plug that might have helped, but colours are:

Brown
Green
Red
Brown/Yellow
Red/Yellow (x2 to the same pin)

If it helps, the part number for the relay is:

34-52-0-005-192

Iain S
aus325
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Fri Apr 28, 2006 5:16 am

In my continuing quest to fix my permanent ABS light, I replaced this relay yesterday with a brand new one... and sadly, it didn't fix my problem. :(

I got it from bmaparts.com in the states for US$25 ..as my local dealer here in aus wanted AU$127 !!!! I wish I could say it was money well spent.
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