ABS WARNING LIGHT

[jazzleeds]

on my 1991 325i the abs warning lamp stays on once the engine has started. what could be causing the problem?

thanks

[Nelly]

Knackered ABS sensor - one on each hub set up, their held in place with a small Allen head stub bolt and oval in shape - process of elimination mate.

Neil.

[Brianmoooore]

Knackered ABS sensor - one on each hub set up,.

Doubt it , if the fault description is accurate. Sensor failure makes the light come back on again after it has gone out, when the car moves.
For the fault as described, early cars have an extra relay near the ABS ECU, which is very fragile, and causes this fault when it fails.
I've never come across this fault on a later car, except for on one of mine which does it intermittently, and always cures itself before I can investigate it!!
There are two relays under the cover of the ABS pump, which I heard can be suspect, especially the one with a diode in it.

[Nelly]

Dam it - i sometimes have ago at beating you to a tech post Brian, and when i do i get it wrong lol.

[jazzleeds]

this morning when i started the car everything is fine, no abs light lighting up. could be a lose connection

[Brianmoooore]

this morning when i started the car everything is fine, no abs light lighting up. could be a lose connection

Never seen it myself, but I've heard that it's possible for the relay pins/sockets in the ABS pump unit to develop a little corrosion.
Easy enough to check!. Unscrew the single screw on the plastic cover over the ABS pump and lift it off. Pull out the two relays and check everything is clean and bright.

[215m3]

I had a fault on my M3. If you started the car and drove off it worked. If the car was started and revved before it was driven off the abs light came on. It could either be the silver relay under the abs unit cover or the one next to the abs ecu. The relay is twice the length of a standard relay for easy of location.

[215m3]

I have a couple of E30 new and unsed relays if that is what you need. Let me know the part number.

[snoops]

this is the same as mine, mines a facelift and the abs light stays on when driving and very rarely goes off but then the beep comes back n its on again