One day my ABS light came on. I checked it out and sure enough there was no abs... when I slammed on the brakes, everything locked up.
Everyone said it was the wheel speed sensor. When I asked how to check which one, the consensus was "have the codes read at Autozone".
First of all, the autozone does not read abs codes. Also, my car is OBD I, so the code reading is different. So I decided to dig into this a little more.
I took out the passenger side dash cover and glove box. The abs controller is on the right side. Then I disconnected the cable to the controller, and started probing. My connector was not 55 pin like other e36's but I had the Wiring Diagram. I tested for continuity at each wheel speed sensor. I got 1060 ohms at each one except the front right which was at 2 mega ohms. So My problem was indded a wheel speed sensor. I attached a copy of the wiring diagram I used.
I also thought that maybe the pump was bad. There was a lot of information about the ribbon wire in the pump needing to be replaced. I found these 2 links which may help anyone trying this repair:
http://www.staffordnet.net/repairs/b...ump_rewire.htm http://www.thetremmels.com/bmwabs.htm Lastly there is a way to force the pump to cycle. This can be used to check it and also bleed air out of the system.
Pull the grey ABS relay from the fuse panel under the hood. Jumper pin 30 to 87 and you should hear it pump away. Bleed the brakes as you normally would, cycle the ABS, then bleed again. Sounds like a lot of fluid, I know. You may need 3 quarts to do it right.
Hope this helps someone out there.
ABS diagnose/repair 
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