Uh.. Question

"Logansteno: Bought a VW?" (logansteno)
02/20/2016 at 00:39 • Filed to: None

What the HELL would cause my ABS to kick on at parking lot speed in the dry and then all the sudden the brake force like tripling and almost sending me through the windshield? That just happened to me in the M3 and it’s never, ever happened before. I have intermittent ABS and traction control lights but I sorta just ruled that to a wheel speed sensor needing replacement. It concerned the shit out of me to say the least.

DISCUSSION (21)

Steve in Manhattan > Logansteno: Bought a VW?
02/20/2016 at 00:46

Brake fluid level, brake lines, master cylinder? ... trying to think of all the components.

bob and john > Logansteno: Bought a VW?
02/20/2016 at 00:49

probably that.

rather that then what happened to me on my bike.

I didnt install the ABS sensor back in properly. coming up to a hwy off-ramp, the bike LOCKED ME OUT of the brakes. (CODE YELLOW) started downshifting and applying the brakes harder and harder. The ABS system realized something was off, and when it recognizes that, it turns off the ABS.

so now I had brakes. But no ABS. With the force I had on the front, i ended up bringing the bike on the front wheel like this:

Kinja'd!!!

without meaning too at 60mph (CODE BROWN, CODE VERY VERY BROWN)

Made it out...but BOY was I careful the rest of the ride to work

Logansteno: Bought a VW? > bob and john
02/20/2016 at 00:52

I need to figure this out quick as I can because I'd rather not have a 3200lb hunk of steel hurtling down the highway and all the sudden the brakes stop working all together.

bob and john > Logansteno: Bought a VW?
02/20/2016 at 00:54

first thing i would check is the ABS tone rings, then the ABS sensors themselves.

if those check out, take a look at the connections to the ABS moduale

Denver Is Stuck In The 90s > bob and john
02/20/2016 at 00:57

I told him to do just that and in the mean time to pull the abs fuse and pump the brakes so its actually driveable until its fixed. No abs is better than malfunctioning abs

LOREM IPSUM > Logansteno: Bought a VW?
02/20/2016 at 01:00

Not sure if applicable on your m3, but modulemaster.com are the folks to talk to if it turns out to be an abs module related issue.

CodyVella > Logansteno: Bought a VW?
02/20/2016 at 01:01

I had this happen many many years ago in an old Pontiac Sunbird. The rear proportioning valve shit the bed and it sent full brake pressure to one rear wheel which caused that wheel to lock (Single channel rear ABS), and the ABS to lose it’s freaking mind.

Bearing in mind this was one of the very first ABS systems on a mass produced vehicle, once the ABS realized something was up, the pedal went straight to the floor, then shot back up with the force of a freight train, all but snapping my leg. All four wheels suddenly locked, then unlocked just in time to stop me from finding the windshield with my face. It would only do this under 20km/h. Mind you, this could only cause this if you’re dealing with single channel rear ABS. I must have checked just about every damn thing on that car before I realized the proportioning valve had enough of life.

-this space for rent- > Logansteno: Bought a VW?
02/20/2016 at 01:02

ABS kicking in is mostly likely a weak/bad wheel speed sensor. The brakes slamming on could be a stability control thing, but I don’t know if e36s have that.

Try this: http://www.m3forum.net/m3forum/showth…

Andrew T. Maness > Logansteno: Bought a VW?
02/20/2016 at 01:02

I can’t help you, but I feel the need to compliment you on a very clean E36.

smobgirl > Logansteno: Bought a VW?
02/20/2016 at 01:08

Our company car has done similar, I'm hoping it's the wheel speed sensor. It's terrifying.

AMGtech - now with more recalls! > Logansteno: Bought a VW?
02/20/2016 at 02:01

Wheel speed sensor is a good guess. It should set faults and you should be able to monitor actual values from the sensors via a compatible scan tool.

One sensor reading a different speed, especially if that speed is still plausible, can definitely cause what you experienced because the car would then think it’s spinning out or locking up etc.

I seem to remember a bunch of 90's Euro cars having issues with solder joints on their ABS module circuit boards. Don’t know if this applies to yours or not though. Pretty simple fix if you have some basic soldering skills. This happened on an 850R I had years ago, there were a bunch of tutorials for it online. Took maybe an hour and no materials cost to fix.

Great job with all the changes and improvements you’ve made to that thing BTW, it looks excellent.

Schaefft > Logansteno: Bought a VW?
02/20/2016 at 08:24

ABS module failure is quite a common problem with E39s due to heat damage (module too close to the exhaust manifold). I wouldn’t be surprised if this is the issue here, considering the part and the location of the module will be the same.

SnapUndersteer, Italian Spiderman > Logansteno: Bought a VW?
02/21/2016 at 23:30

Get it scanned, dammit

Logansteno: Bought a VW? > SnapUndersteer, Italian Spiderman
02/21/2016 at 23:37

I’m scanning it tomorrow at tech school so

SnapUndersteer, Italian Spiderman > Logansteno: Bought a VW?
02/21/2016 at 23:42

Did the ABS light come on after/during this happened?

I’m assuming your wheels locked when you say the brake force tripled? Were you trying to activate ABS at the beginning of this happening?

Answering those questions can help me help you better

Logansteno: Bought a VW? > SnapUndersteer, Italian Spiderman
02/21/2016 at 23:44

The ABS light was actually off when this happened. For the first time the entire day which was really weird.

I’m pretty sure they locked. I wasn’t trying to do anything but slow down to park in front of my house.

SnapUndersteer, Italian Spiderman > Logansteno: Bought a VW?
02/21/2016 at 23:53

Were you braking aggressively though when the ABS kicked in?

Did the light go on after it happened?

I had something like that happen to me once. I was braking aggressively (riding ABS on purpose) and then my wheels locked. The car had died on me because it hit a weird bump, which killed the car mid-braking, which in turn locked the tires and flat-spotted them. It wasn’t an ABS problem.

I see lots of recommendations here, but there are so many diag paths that I don’t advise to check any of them until you scan it tomorrow, simply because it’s shooting in the dark

Logansteno: Bought a VW? > SnapUndersteer, Italian Spiderman
02/21/2016 at 23:58

Not really. Just coming down from maybe 15 to 5 mph. Barely pressing the pedal.

Nope.

I haven’t ever gotten the car to do it again since it happened (and truts me I’ve tried) so it maybe have been some really weird accident. Of course the ABS has been 100% inop since then so who knows.

SnapUndersteer, Italian Spiderman > Logansteno: Bought a VW?
02/22/2016 at 00:23

If it’s inop, then the light should be permanently on now, not intermittent as you mention in the post. Is it?

Logansteno: Bought a VW? > SnapUndersteer, Italian Spiderman
02/22/2016 at 00:24

Yep after that it's been solidly on.

SnapUndersteer, Italian Spiderman > Logansteno: Bought a VW?
02/22/2016 at 00:56

I’m pretty sure I have spare fornt and rear ABS sensors, so if your scan reveals you need either, lemme know and I’ll send you one.