New tires, ABS light

[FourG63 97GST]

Well I just put my new tires and now i notice my anti lock brakes light is coming on. What will cause this?
the only reason I can come up with is that front and rear tires are different sizes. the front are 215/40/16, and the rear is 205/55/16.
I'm not sure yet cuz i put the tires on like an hour ago. but the light doesn't seem to come on under normal driving(under 3k rpms) or maybe it comes on after a certain time,i'm not sure yet.
but when the ABS light comes on does it means it's disabled?
What I really want to know is, is that normal or the shop messed up brakes?

 

[pilotleston]

It must be because of the differente tires sizes...
You must use same tyres all around or your ABS will be disabled when it detects that the wheels are spinning differente for a long time.

 

[turboholic]

-Your front tire is smaller in diameter compare to the rear, the ABS is counting your tires rpm and detect that your front tire is rotating faster than the rear, that why ABS flag an error.

-You can use different size of tires between front and rear but as long as the diameter of the tires are relatively close. ie: my winter tires are 205/55/16 front and 225/50/16 rear, here is what I'm talking about.

 

[FourG63 97GST]

Thanks alot, that explained it very well

 

[nined2tsi]

Well my abs light came on after i replaced my back brakes (pads and rotors.) It started doin funky shyt for the first 10 min of driving, i shut my car off then started it again, then my brakes were working fine, but my abs light is still on. any suggestions? i dont really care about abs, personally i think it sucks.

 

[FourG63 97GST]

yea It does, tonite I test then to see if the ABS really works the way it should, the ABS light wasn't on, so they where functions. I looked to see if there was any cars behind. I was clear, so I slammed the brake. the front wheels locked up an the car pulled to the left pretty hard. I was going like 40mph.

 

[whitegst97]

Hey all, after doing some break pad work, my car has been turning on the ABS light once in a while. It does not happen all the time. Sometimes I take a trip somewhere and it's on all the way...then, when I'm ready to leave and I turn on my car again it doesn't stay on...It's acting weird, and I can't tell why. I have been reading most of the posts here and well, I have even tires all around and I haven't done any major work on the break system...any help would be highly appreciated. Thanks.

 

[Omega]

Have a look at the ABS ring. It almost looks like a gear. It has evenly spaced grooves in it. As it spins, the computer counts the signal coming from the pick-up. Make sure that the pick-up it clean and connected properly. Also make sure the ring is clear. You might have whacked the pick-up so that it can't read the ring.

 

[whitegst97]

Thanks for the reply, now, where exactly is the ring? Can someone send me some pics or give me an idea of where to look for it, Thanks alot