Rear abs issue?????

superd21007 · 11-10-2012, 08:27 AM

Hey all... so I git this new weird issues going on... When I brake to a complete stop, my drivers rear anti-lock brake triggers.

Let me give details: It only happens when I am to a complete stop. Doesn't happen until the speedo is at the last hash mark and I am a slow crawl. The pedal vibrates and makes the classic abs sound until I am stopped. No lights come on at all. Braking performance is not affected. DOES NOT happen while braking while driving. NO other wheel are doing this, I can hear the chatter at that corner. Brakes are all new as of 8 months ago with brand new calipers.

No shimmy's, vibrations or other noises while driving or braking. I did notice that when this happens the speedo needle drops to zero immediately even though I am still moving slowly.....

Weird as ****.... any thoughts on this??? Bad sensor? Traction control issue??

Turned off traction control and it still happened....

Thanks!!

scarede46er · 11-10-2012, 09:01 AM

Speed sensor most likely. I think one of them controls the speedo.

WDE46 · 11-10-2012, 09:31 AM

Quote:

Originally Posted by scarede46er

Speed sensor most likely. I think one of them controls the speedo.

Agreed that it's probably a speed sensor. Weird that the rear wheels would control the speedometer though. Those wheels can spin faster than the car is moving if you break traction. I would think they would go with the front, non-powered wheels so there would be no possibility of this.

superd21007 · 11-10-2012, 09:51 AM

alright, cool.... easy fix i hope! that does make sense as to why the abs is triggered.

thanks for the thoughts

WDE46 · 11-10-2012, 09:58 AM

Quote:

Originally Posted by superd21007

alright, cool.... easy fix i hope! that does make sense as to why the abs is triggered.

thanks for the thoughts

Usually the sensors throw a code when they are bad though.

superd21007 · 11-10-2012, 10:06 AM

where does the sensor read? Looks like the bearing or axle spindle? Didn't put this together for some dumbass reason, but had that wheel bearing replaced the other day and haven't really driven until yesterday. Maybe it got damaged or somehow gunked up the sensor.

shanneba · 11-10-2012, 10:24 AM

Make sure the sensor is back where it belongs and is connected correctly.
http://tis.spaghetticoder.org/s/view.pl?1/04/44/32

WDE46 · 11-10-2012, 10:44 AM

Quote:

Originally Posted by shanneba

Make sure the sensor is back where it belongs and is connected correctly.
http://tis.spaghetticoder.org/s/view.pl?1/04/44/32

I would unplug it and clean it with electrical contact cleaner or MAF sensor cleaner. Even if they did put it back right, it could be dirty.

scarede46er · 11-10-2012, 05:20 PM

^Isn't it a hall sensor? Why would it be affected by dirt?

Cheet22 · 11-11-2012, 12:52 AM

Had similar problem recently.

Changed let rear sensor and sorted it, well almost. After i changed that, it would occasionally flicker the dsc light an this would then mess with throttle and braking (assume it thought i was skidding)

So replaced other rear sensor. Sorted.

Take your time undoing them, if original they are easily rounded!

Also, see if you just press dtc button, that does not switch everything off. Hold it down until brake light also comes on and see if it still does it then too.

WDE46 · 11-12-2012, 06:08 AM

Quote:

Originally Posted by scarede46er

^Isn't it a hall sensor? Why would it be affected by dirt?

I'm referring to the sensor connector, not the sensor itself.

superd21007 · 11-16-2012, 01:55 PM

Follow up:

Thanks for the solid call guys.... finally had a chance to get to this and found out that all the ground sh$t from the bearing going so bad was stuck to the magnet. I couldn't believe how much really!! lol Anyway still waiting for my new one to be delivered as this one fell apart while trying to pull it out as it was the original I think.

11-10-2012, 08:27 AM	#1
superd21007 Registered User Join Date: Mar 2012 Location: New Haven MI Posts: 24 My Ride: 99 323i View My Garage	Rear abs issue????? Hey all... so I git this new weird issues going on... When I brake to a complete stop, my drivers rear anti-lock brake triggers. Let me give details: It only happens when I am to a complete stop. Doesn't happen until the speedo is at the last hash mark and I am a slow crawl. The pedal vibrates and makes the classic abs sound until I am stopped. No lights come on at all. Braking performance is not affected. DOES NOT happen while braking while driving. NO other wheel are doing this, I can hear the chatter at that corner. Brakes are all new as of 8 months ago with brand new calipers. No shimmy's, vibrations or other noises while driving or braking. I did notice that when this happens the speedo needle drops to zero immediately even though I am still moving slowly..... Weird as ****.... any thoughts on this??? Bad sensor? Traction control issue?? Turned off traction control and it still happened.... Thanks!!

11-10-2012, 10:24 AM	#7
shanneba Registered User Join Date: May 2008 Location: Indiana Posts: 1,856 My Ride: 2003 330Ci View My Garage	Make sure the sensor is back where it belongs and is connected correctly. http://tis.spaghetticoder.org/s/view.pl?1/04/44/32 __________________ Join BMWCCA Discounts on new and CPO cars. Most Dealers offer a parts discount, BMP Design 10% off

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11-10-2012, 09:01 AM	#2
scarede46er Registered User Join Date: Aug 2012 Location: Clemson, SC Posts: 738 My Ride: 2001 BMW 325i ZSP View My Garage	Speed sensor most likely. I think one of them controls the speedo.

11-10-2012, 09:51 AM	#4
superd21007 Registered User Join Date: Mar 2012 Location: New Haven MI Posts: 24 My Ride: 99 323i View My Garage	alright, cool.... easy fix i hope! that does make sense as to why the abs is triggered. thanks for the thoughts

11-10-2012, 10:06 AM	#6
superd21007 Registered User Join Date: Mar 2012 Location: New Haven MI Posts: 24 My Ride: 99 323i View My Garage	where does the sensor read? Looks like the bearing or axle spindle? Didn't put this together for some dumbass reason, but had that wheel bearing replaced the other day and haven't really driven until yesterday. Maybe it got damaged or somehow gunked up the sensor.

11-10-2012, 05:20 PM	#9
scarede46er Registered User Join Date: Aug 2012 Location: Clemson, SC Posts: 738 My Ride: 2001 BMW 325i ZSP View My Garage	^Isn't it a hall sensor? Why would it be affected by dirt?

11-11-2012, 12:52 AM	#10
Cheet22 Registered User Join Date: Oct 2012 Location: Hamilton, scotland Posts: 11 My Ride: E46 330i View My Garage	Had similar problem recently. Changed let rear sensor and sorted it, well almost. After i changed that, it would occasionally flicker the dsc light an this would then mess with throttle and braking (assume it thought i was skidding) So replaced other rear sensor. Sorted. Take your time undoing them, if original they are easily rounded! Also, see if you just press dtc button, that does not switch everything off. Hold it down until brake light also comes on and see if it still does it then too.

11-16-2012, 01:55 PM	#12
superd21007 Registered User Join Date: Mar 2012 Location: New Haven MI Posts: 24 My Ride: 99 323i View My Garage	Follow up: Thanks for the solid call guys.... finally had a chance to get to this and found out that all the ground sh$t from the bearing going so bad was stuck to the magnet. I couldn't believe how much really!! lol Anyway still waiting for my new one to be delivered as this one fell apart while trying to pull it out as it was the original I think.