I recently replaced brakediscs and -pads on both sides, rear.

At first I forgot to put the plate on the disc that the ABS-sensor registeres, from the old disc to the new one, so I when I started the car I immediately got a constant yellow ABS-light, and a blinking red "brake-light" accompanied by 3 beeps.

So I deassembled the brakes once more, cleaned the sensor and banged out the old plate and put it on the new disc.

What happens now is that the ABS is applied every time I brake on dry asphalt, which it offcourse shouldnt be doing. Its like this for about 3-4 minutes (perhaps until I reach a certain speed?), and then the yellow ABS-light and the red light with 3 beeps comes on again, and the ABS stop functioning.

Anyone know what might be the problem? The mentioned plates are pretty rusty. Maybe I made them a little uneven/crooked when putting them on the new discs with the help of a hammer? :-)

Thanks for any reply.

1997 A4, 1.6 liter fwd.

 

ya found a dyi about it, its a loose connection in the acutal abs unit it seld, need sauldering or however you spell it check youtube, i can post the link but the guy who posted it is : idusclothing and the title of tyhe vide is 1999 a4 abs module fix.

hope this helps you im about to give it a shot on mine next week.

 

The ABS sensor doesn't watch anything on the disc. I'm not sure what plate you're talking about. The sensor watches a toothed gear on the axle shaft. When the sensor sees the gear stop moving, it knows the wheel is locked up and kicks on the ABS. The beeping you're talking about is because the ABS unit is telling you there is a problem. If the ABS unit was dead, the ABS light on the dash wouldn't be lighting up. More than likely, there's something wrong with one of the ABS sensors on the rear since you just did the brakes back there. If you can get it scanned you'll know which one. Not sure if a regular OBDII will do that or if you need vagcom. It's possible that there is just a buildup of rusty metal flakes on the end of the sensor. If that's the case, you just clean them off and you should be good to go.

 

I was thinking about it and realized that I was assuming you were talking about a quattro. I now see you have a FWD. So I'm probably not right about the rear ABS sensor. But I still think there's nothing wrong with your ABS unit.

 

DRGREVE, at what speed does the ABS engage on dry asphalt? ALWAYS? OR only when you get to a certain speed? I would also check your brake fluid level if you haven't already done so.....

as Jeckel says, the abs sensor (if you have them), is behind the rotor on the axle and reads the gears/cogs inside the axle shaft.....

 

As I have a FWD the mentioned plate is attached to the rear of the brake disc. When I banged it in place it got crooked creating to much distance for the sensor to register wheel speed I guess. So I disassembled the brakes, hammered it back to its original state (almost at least) and voila, problem fixed. I appreciate the replies none the less.