ABS warning light

[paul]

Since having my discs and pads changed on my S2 16v turbo the ABS light has started to come on when driving at normal speeds( After stopping the engine and restarting it may stay off for some hours /days. I hoping that with out going through all the circiut diagrams some might know were the earth wires or supply wire go / come from to the ABS control unit and or the ABS ecu. I have checked that none of the ABS wheel sensors are dis-connected. Does any Know more?

[adam atfield]

The usual fault on the abs is the speed sensor cables that are mounted in the supension uprights. The cables are cliped on to the supension legs and over time the movement of the suspension causes the cables to fracture. The only way to check these is with an ohmeter conected to the two connections of the cable and then try to stretch the cable , you will proably find the break will be were the cable is clipped to the suspension leg. It is important to stretch the cable as you test it otherwise you will not find the break in it. GOOD LUCK !

[Craig]

I had a the ABS light come on when I was in southern Italy, 1000miles after I overhauled the suspension and brakes before leaving the UK for a fortnights holiday. I had to finish my holiday with the ABS inoperative but when I returned I checked it over and found that on reassembly the sensor had become slightly closer to the phonic wheel on the driveshaft and re-shimming it back to the correct tolerence cured the fault. This was a strange thing to happen considering that I had not removed the sensor from the mounting, only the driveshaft from the hub. Try checking the gap between your sensors and the phonic wheel they should be between 0.55mm and 0.85mm.