garyo

Hi Chaps,

Any idea what could be going on with my ABS? My problem is as follows:

Just after starting the car, the ABS light is illuminated as usual. After driving 100 metres or so, it extinguishes as usual. At any speed over 10mph, the brakes work well, and I can brake so hard in the wet that I can provoke the ABS into engaging and it works well.

If I coast to a stop braking lightly, then 100% of the time, as the speed drops to around 11mph, the ABS engages and continues to engage down to around 5mph. This is damn dangerous in commuting traffic. Below 5pm the brakes work well. After doing this once, the ABS warning light continues to be extinguished. If I repeat the process around three or four times, eventually the ABS light will come on, and then the brakes work perfectly at any speed (non ABS assisted obviously)

I'll looked at all the basics such as uneven tyre wear, uneven pressures, I've had a tooth brush on all of the ABS sensor teeth and given them a good clean... and now I'm stumped.

There are no CEL codes apart from one related to the emissions air pump.

Cheers

Gary

martin j

I reckon one of the sensors at the wheels is playing up.?

m1bjr

I thought the dash lamp should go out once the engine starts (self check completed)
If it waiting until you are rolling then I would also say a failing wheel ABS sender.
Had this on an older Audi, but it only did it in reverse

garyo

I've just been watching some startup vids on youtube and you're right actually - hopefully that'll make the fault easy to track down. I've just been looking through the archives and it seems that my scanguage won't read an ABS fault anyway. It's not 100% clear whether there's a paperclip method for reading the ABS code.

I guess I'll get the multimeter out and check the sensors for anything obvious.