View Full Version : ABS light just turned on :(

11-24-2005, 01:41 AM
hey guys my ABS light just came on today out of nowhere...i didnt experience anything different with the performance of the car or braking...what could be the problem*sad* *sad* ...thanks for the help

11-24-2005, 01:43 AM
if the light is one, your ABS shouldn't be working. I have the same problem on my car, its cause the passenger side front speed sensor is shot!

11-24-2005, 01:45 AM
so would that mean if i brake really hard my wheels will lock up? did you fix yours yet or are your leaving it for now? im probably going to get it checked out at maranello tomorow

11-24-2005, 01:47 AM
I'm just leaving mine the way it is.... maybe i'll get around to it just don't see it being that important

11-24-2005, 02:05 AM
so does that mean if i brake really hard its going to lock up all of my wheels?

11-24-2005, 02:13 AM
Ya.... sorry, i forgot to answer that. Yes, you have NO ABS as long as that light is on!!

11-24-2005, 03:29 AM
ahh shlt...

11-24-2005, 03:34 AM
oh ya.... it REALLY comes in handy in the winter

11-24-2005, 05:47 AM
so i should get it fixed asap then?

Justin e36
11-24-2005, 06:31 AM
depends.. some people prefer no ABS.
Is your ABS on as soon as you turn on your car now too? Is it always on?

As Soldomatic said, the typical cause is one of your speed sensors on your wheels is shot. Each wheel has a speed sensor attached to it, your ABS computer monitors the speed of each wheel... this is how it calculates how to pulse the ABS brakes when it detects them locking up suddenly. If one of your speed sensors is giving a reading that is either too fast, or too slow, then your ABS light will come on as the computer will not be able to calculate properly.

This can also happen if you have one wheel that is worn more than the others, or if one wheel is brand new, and the others are almost bald. Also if you put two wheels, say on the back, that have a larger diameter than the front wheels (which happens sometimes when people switch over to winter tires.)

In either case, usually the speed sensor is suspect. If your wheel sensors are fine, then the ABS relay (located in your fuse box) can possibly be dead, and if that is fine, then your ABS brake pump (attached to your brake master cylinder).

Maranello BMW can check this for you, as they have the code reader. Also most specialist mechanics can do this for you. If you do a search on the forum for Bimmersport, you can call that shop as well... they'll be cheaper than Maranello, but they might be booked up tomorrow.

Hope this helps,

11-24-2005, 10:54 PM
^thanks for the info justin...its at maranellos right now...but i didnt get the abs checked because today the light wasnt even on...weird...could it be the sensors then?