Major ABS problem, Need to identify the problem Options

[Panic]

I took my celi in for its MOT last weekend and it failed on the fact the ABS doesn't work. As it turns out the not very nice man (who I'd quite like to punch right now) has disconnected the light from the dash so it doesn't show up.

I need to know what the most likely problems are. It locks all four wheels under heavy braking and all the sensors and relays seem to be working and getting power. My mate is doing the repairs at his garage for me but hasn't worked on a 6th gen before

I really need help with this as I can't drive until I get it sorted

[4v6]

I can add another test to that for you!

With the vehicle raised off its wheels, disconnect each of the sensors in turn and attach a digital voltmeter to the sensor terminals.
Set the meter to read Volts AC (alternating current) then spin the wheel by hand.
You should generate a voltage if the sensor and reluctor ring on the driveshaft is good, can go as high as a couple of hundred volts at the kinds of speeds the car can get to, but in this instance, all we want to see is a nice AC signal telling us that the sensor is seeing the teeth of the abs reluctor ring as it passes thru the magnetic field of the sensor.

Hope thats some help!

This post has been edited by 4v6: Jan 29, 2012 - 9:09 AM