1995 E36 M3.
Symptom:
Start car, all is ok.
Brake hard and engage ABS, ABS light comes on, and ABS seems to disable.
The rest of the session is without ABS.
Turn car off, restart car, all is ok.
FYI, I haven't had the time to check sensors yet. But just wondering, are the above symptoms typical of a bad sensor, bad ABS computer, other?
Same here, except mine comes on without braking on warmup lap first session. Doesn't come back for the rest of the weekend. Lots of folks say it is the pedal travel sensor on the front of the booster unit, but I haven't tried replacing it yet.
'95 M3 S54 Track Toy
'19 X5 40i M-Sport
'16 Cayman GT4
‘23 GR Corolla
FYI found this. Looks like a pretty extensive debug guideline, and specifically for the E36 chassis.
https://blog.bavauto.com/14248/bmw-d...es-and-others/
I used that procedure to diagnose my issue. For me, it was a cut sensor wire - different symptoms from you.
I've had the same issues before. Once it was the ground under the dash on the passenger side. Another time it was a front abs sensor pin in the connector that snapped when I plugged it in.
That's correct, exact same symptoms. I went overboard though trying to diagnose and resoldered the pedal travel sensor and the entire abs unit when I was trying to diagnose. Check the easy stuff first like grounds and do some simple multi meter tests
Interesting. Thanks. A loose ground kinda makes sense though. Could get shaken loose by violent braking.
I had a similar issue, though sometimes the ABS light would come on before any hard braking. I replaced all 4 ABS sensors and that didn't fix it. Turned out to be the pedal travel sensor.
Thanks, will check that next.
I'd read the OEM code or have it done. The ABS unit has detailed chassis-specific codes. I saved a lot of doing doing that (bad wheel sensor in my case).
Dan Chadwick
Boston Chapter BMW CCA Instructor Development.
Near-Orbital Space Monkeys, E30 M50-ish
Driving Evals on-line evaluations for Driving Schools. Paper forms are just wrong.
So, it's a 95, obdi.
Do the ABS faults show up via the pedal stomp test?
If you have the stomach for it, and and old computer with a serial port, get INPA and the tinyADS adapter. Then you can get the codes from the ABS unit.
Chris
Likely a torn solenoid ribbon wire inside the ABS pump, re-wire it. But of course, do you homework and check the easy/obvious things first.
Well crap, my friend, all around good mechanic, and more importantly european car shop owner, hooked up his brand new 'spensive SnapOn diagnostics tool, and said it 'couldn't communicate with the computer'.
I'm guessing a BMW shop would be quite costly to read these codes.
Is there any reasonably priced scanner that can do this?
EasyDis/GT1...find someone in your area with a laptop setup via the forums. Best investment I ever made...for BMWs. Typically, for 95M3's I find the brake switch distance sensor is the problem.
Don
I was quoted $120 and $150 from local BMW shops. Ug. Ima do some basic resistance diags this week before spitting out that much.
Odd I can't get this to occur anywhere except track.
Not a huge deal, more than not having ABS on track, it's the surprise of not having ABS at some random hard braking point.
2 track days coming up this weekend!
I've been tracking my M3 regularly since 1999. I've had two "off-course excursions" out of about 200 days on track. Neither would have happened if my ABS had been turned off. Hard to say if there were occasions that ABS might have prevented an issue.
'95 M3 S54 Track Toy
'19 X5 40i M-Sport
'16 Cayman GT4
‘23 GR Corolla
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