Welcome to Bimmerfest -- The #1 Online Community for BMW related information! Please enjoy the discussion forums below and share your experiences with the 200,000 current, new and past BMW owners. The forums are broken out by car model and into other special interest sections such as BMW European Delivery and a special forum to voice your questions to the many BMW dealers on the site to assist our members!

Please follow the links below to help get you started!

Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > X Series > X3 F25 (2011 - current)

X3 F25 (2011 - current)
The latest X3 brings some added style and some new features to the BMW SUV family. Talk about the new F25 now!

Reply
 
Thread Tools Display Modes
  #1  
Old 06-14-2013, 04:57 PM
longhornfan longhornfan is offline
Registered User
Location: dallas, tx
 
Join Date: Jun 2013
Posts: 5
Mein Auto: 2013 x-3
X-3 ABS system

I am wondering if anyone else has had trouble with the ABS system initiating under ordinary braking, weather and road conditions. I have had two instances where I was routinely braking and the system has kicked in. Yesterday, everything locked up as I slowed for a red light and I lurched forward at a light and hit the rear of the car in front of me. BMW service says everything checks out fine and there are no fault messages. They claim there was something about the road condition that caused this.
Reply With Quote
Advertisement
  #2  
Old 06-14-2013, 05:42 PM
grebersole grebersole is offline
Registered User
Location: USA
 
Join Date: May 2013
Posts: 23
Mein Auto: 2014 X3 xDrive 35i
X-3 ABS system

What year and model is your vehicle?


Sent from BimmerApp mobile app
Reply With Quote
  #3  
Old 06-14-2013, 06:00 PM
The X Men The X Men is offline
Officially Welcomed to the 'Fest
Location: MA
 
Join Date: Mar 2012
Posts: 5,068
Mein Auto: 2012 535xi 2013 X3 35i
I don't understand, how did the ABS make you lurch forward?
Reply With Quote
  #4  
Old 06-14-2013, 06:09 PM
longhornfan longhornfan is offline
Registered User
Location: dallas, tx
 
Join Date: Jun 2013
Posts: 5
Mein Auto: 2013 x-3
X-3 ABS system

I have a 2013 X3
I can only tell you what it felt like and what the dealership attributed it to since I am not very familiar with how the ABS works. It felt as if my brakes locked up and then it felt like a pumping sensation that caused the car lurch forward. I was simply braking for a red light in dry conditions. Dealership said it sounded like I was describing how the ABS system would react to slick pavement to keep from skidding .
Reply With Quote
  #5  
Old 06-14-2013, 07:33 PM
aberrant aberrant is offline
just some random guy
Location: San Francisco
 
Join Date: Apr 2013
Posts: 185
Mein Auto: 2014 X3 35i
X-3 ABS system

Are you sure it wasn't the drag produced by the dynamic charge system? That comes on at slow speeds and produces very noticeable engine drag. I don't know that I'd describe it as 'lurching forward' though.



Sent from BimmerApp mobile app
Reply With Quote
  #6  
Old 06-15-2013, 06:12 AM
Drewsky's Avatar
Drewsky Drewsky is offline
Officially Welcomed to the 'Fest
Location: Tampa, FL
 
Join Date: Mar 2002
Posts: 331
Mein Auto: '14 X3 35i-M Space Grey
A couple armchair-quarterbacking notes:

-you said the system "locked up". ABS never locks the wheels. When abs engages, it is QUITE noticeable: you feel it in the brake pedal and you may hear/feel a pulsing "shudder" throughout the vehicle.

-you didn't say how fast you were going or how hard you were braking. As other posters have commented, the engine does a good deal of "engine braking" and it is very evident when very gently slowing. When the vehicle downshifts it can feel like a decrease in braking. If this resulted in a collision you are following way too close to the car in front of you!

-The human body isn't very good at interpreting changes in the change of momentum. For example, a change from a "hard stopping" deceleration to a "gentle stop" deceleration can actually FEEL like an acceleration. Thus your "lurch foward" you felt was most likely a change in the slowing speed.

-Hitting a slick spot will decrease overall braking to the wheels slightly. As mentioned above, this decrease in braking can feel like an acceleration. (fun fact: engaging ABS on a motorcycle *REALLY* makes this feel evident!! It is quite a strange feeling)
Reply With Quote
  #7  
Old 06-15-2013, 06:23 AM
The X Men The X Men is offline
Officially Welcomed to the 'Fest
Location: MA
 
Join Date: Mar 2012
Posts: 5,068
Mein Auto: 2012 535xi 2013 X3 35i
I agree, the ABS should not lock the brakes, in fact, it is a anti lock system to prevent locking. Sounds more like a braking problem to me, the brake froze somehow and then let go altogether causing the lurch forward.
Reply With Quote
  #8  
Old 06-15-2013, 10:45 AM
Liverman's Avatar
Liverman Liverman is offline
Officially Welcomed to the 'Fest
Location: Teller County, Colorado
 
Join Date: Jun 2005
Posts: 527
Mein Auto: '14 X3 35i / '03 F350
Quote:
Originally Posted by The X Men View Post
I agree, the ABS should not lock the brakes, in fact, it is a anti lock system to prevent locking. Sounds more like a braking problem to me, the brake froze somehow and then let go altogether causing the lurch forward.
As aberrent stated - that is the dynamic charge or energy regeneration system. You'll see it's action in the display under the tach. It is automatically turned on and off by the car's computer. I do not know the parameters used by the computer to decide when to engage and disengage, but it appears (based on my 3000 mi driving experience) to be when coasting or braking.

When it is engaged, there is a noticeable drag. When it releases the sensation is the car lurching forward since drag is reduced. I have only noticed the drag/release when I am coasting or have the brake only very lightly engaged.

From your description, it sounds like it is working as designed.

But maybe I don't understand - when you say "everything locked up" and "brake froze" did the wheels lock and result in screeching tires and marks on the pavement?
__________________
Greg

Our BMW: '14 X3 35i, Deep Sea Blue, Black Nevada Leather, Fineline Wave Wood, Satin Aluminum Roof Rails, Premium Pkg, Cold Weather Pkg, Navigation System, Driver Assistance Pkg with ALL them cameras, Premium Sound
Our truck: '03 Ford F350, 7.3L turbo-diesel, 4WD, Lariat package, Lear topper, cow catcher, Blue over Grey (Go Rice!)


"Old Faithful's just a fountain compared to the glory of true love" -- John Prine
Reply With Quote
  #9  
Old 06-16-2013, 08:24 AM
poker838 poker838 is offline
Officially Welcomed to the 'Fest
Location: Toronto
 
Join Date: Jul 2011
Posts: 196
Mein Auto: F25 x28 n52 + n20 / B8 A4
Gents, there is no Hybrid-style brake energy capture on this BMW. It is purely a marketing spin. We only get a trick alternator that only charges when you're off throttle. It is not connected to the brake system and should not provide any meaningful deceleration

Last edited by poker838; 06-16-2013 at 08:32 AM.
Reply With Quote
  #10  
Old 06-16-2013, 08:31 AM
The X Men The X Men is offline
Officially Welcomed to the 'Fest
Location: MA
 
Join Date: Mar 2012
Posts: 5,068
Mein Auto: 2012 535xi 2013 X3 35i
Quote:
Originally Posted by poker838 View Post
Gents, there is no Hybrid-style brake energy capture on this BMW. It is purely a marketing spin. We only get a trick alternator that only charges when you're off throttle. It is not connected to the brake pedal.
I agree, Its not like the engine is being drag down by a huge drive motor as in a hybrid. The BMW regenerative system is just a normal size alternator dragging the engine, which does not amount to much drag.
Reply With Quote
  #11  
Old 08-19-2013, 03:15 PM
longhornfan longhornfan is offline
Registered User
Location: dallas, tx
 
Join Date: Jun 2013
Posts: 5
Mein Auto: 2013 x-3
After my post, I had a second incident which allows me to describe a little better. I was slowing for a red light and I could tell that I was not getting full power in the brakes, followed by a surge of acceleration. Had there been any oncoming traffic, I would have sailed into the intersection. As it was i was able to make a turn at the corner and stop just outside the intersection. Engineer for BMW of North America has inspected and can't identify a problem.
Reply With Quote
  #12  
Old 08-19-2013, 06:08 PM
Drewsky's Avatar
Drewsky Drewsky is offline
Officially Welcomed to the 'Fest
Location: Tampa, FL
 
Join Date: Mar 2002
Posts: 331
Mein Auto: '14 X3 35i-M Space Grey
Quote:
Originally Posted by longhornfan View Post
After my post, I had a second incident which allows me to describe a little better. I was slowing for a red light and I could tell that I was not getting full power in the brakes, followed by a surge of acceleration. Had there been any oncoming traffic, I would have sailed into the intersection. As it was i was able to make a turn at the corner and stop just outside the intersection. Engineer for BMW of North America has inspected and can't identify a problem.
I reread all of your posts. This one makes as much sense as the rest of them. First you say the brakes lock up, now you say that they aren't doing anything.

It sounds to me like the problem is a faulty driver module located behind the steering wheel. Replace that and the problems will clear right up.
Reply With Quote
Reply

Bookmarks


Forum Navigation
Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > X Series > X3 F25 (2011 - current)
Today's Posts Search
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On



Forum Jump


All times are GMT -7. The time now is 01:03 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
© 2001-2011 performanceIX, Inc. All Rights Reserved .: guidelines .:. privacy .:. terms