Subject: I have the same problem with ABS Author: davidc (moderator) : member since December, 2003 : 10337 posts Posted on: 2005-11-18 14:16:54

on my '86 735i. The light is off on startup, but illuminates after only a few feet of motion.

I've cleaned and checked all four ABS sensors. The put out an alternating voltage, measured with a voltmeter on AC, but without an oscilloscope it's impossible to tell if the waveform is regular. At least it changes, so I'm inclined to believe that the sensors are good. I also tried replacing the ABS control module with a replacement from a junkyard. Same problem.

The only thing remaining, it seems to me, is the wheel hubs themselves. The teeth are quite rusty but none appear to be missing any grooves/teeth. I'm not sure how they appear when new, though.

I'd like to find a way to determine exactly which wheel is causing the problem, lest I eventually give up and replace all four wheel hubs.

Anyone know the price on new ABS wheel hubs and the procedure to intall them?

David Cecil

'97 740iL, 131k miles
'92 750iL, 82k miles
'86 735i, 99k miles

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• Any way to test the ABS pulse generators? - cfisher 2005-11-17 11:09:21 (478 views)
  • Yes: Any way to test the ABS pulse generators? - jack8272 2006-01-10 15:07:36 (378 views)
    • I'd like to see that. Can you post it here or email it to me? (nt) - davidc 2006-01-10 16:08:07 (378 views)
      • Re: I'd like to see that. Can you post it here or email it to me? - jack8272 2006-01-10 22:39:01 (412 views)
  • Here's a tidbit for ya. - Gcracker 2005-11-21 21:26:47 (472 views)
    • Thanks. I will start with the sensors first, because the teeth - cfisher 2005-11-23 11:09:52 (424 views)
      • Update. - cfisher 2006-01-03 18:34:23 (369 views)
        • Is this the ABS pulse generator you're talking about? (pic) - davidc 2006-01-04 18:28:41 (610 views)
          • that's the one. (nt) - cfisher 2006-01-05 12:32:10 (339 views)
            • BTW, what's a good price for the ABS pulse generator? (nt) - davidc 2006-01-06 19:28:27 (393 views)
              • I paid $110 for one from the dealer with the BMWCCA discount. - cfisher 2006-01-09 12:06:18 (328 views)
        • Since you may need to remove the sensor at the - kff 2006-01-04 09:46:28 (367 views)
          • I'll stick with the heat shrink or tape. - cfisher 2006-01-04 13:55:39 (347 views)
    • Did you replace the rear hubs yourself? - davidc 2005-11-22 00:45:22 (410 views)
  • I think you can check them for continuity, but to check - kff 2005-11-17 14:36:14 (419 views)
    • I guess I've narrowed it down... maybe? - cfisher 2005-11-18 11:06:24 (422 views)
      • I have the same problem with ABS - davidc 2005-11-18 14:16:54 (441 views)
        • My wheel hubs look good, and are not rusty at all. - cfisher 2005-11-18 14:50:26 (427 views)