Anti Lock Brake failure

[e30fr3@k]

It seems something else on my car breaks with every rising sun, and today's problem is my antilock brake system. I was driving on the freeway and the "antilock" light came on. It's not a fluke, the brakes really are screwed up. Later on, the light went out, but whenever I used the brake, it seemed that that ABS was engaging everytime. The pedal would pulsate even at 10 mph. The light came on again and the ABS is completely malfunctioning (which doesn't bother me beside the light). Which part in the system is being stupid with me? I don't know how the system works, so I can't begin to guess. Thanks in advance guys.

 

[xLibelle]

bump... my abs has "acted funny" before as well, but not like this.


i'd like to know whats up with this


first thing i would do is replace the abs sensors and see where you go from there.

 

[poboyis]

check the abs relay under the dash, have you ever had to jump start the car? if so the relay may have fried, it has a lil fusible link in it that acts as an overload protection. the link may be connecting in and out giving you that erratic abs action. $20 from BMW for a new one

 

[e30fr3@k]

Thanks guys...It's really wierd..I'm thinking it's not the relay just because everytime I turn the car off and then back on, the light goes away. I'll both the relay and the sensors anyway. I've taken the tires off frequently, but never actually seen the abs sensor. Thanks for the input. If anyone else has ideas, please help!

 

[epj3]

Actually the first thing you need to try is cleaning EVERY ABS sensor. They are magnetic so pick up shards of metal, brake dust, etc. They aren't supposed to but of course they do.

It will most likely fix your problem. It fixed mine when my car seemed to have the ABS kick in sometimes.

 

[e30fr3@k]

ya, so I looked at the sensors and they both had metal shards, but that's not the problem. My left ABS sensor cable is badly cut up and will probably need replacing.

 

[equate]

do that and if that dosnt fix it look at the overload relay, its right above the ABS brain under the kneee bolster, you will need a 10mm to take the brain off (looks just like the ECU) and the relay will be clipped right above it, take a pliers and take the metal cover off and see if the fuse is blown. If it isnt replace the "brain" i have an extra one if you need it