Abs light

Ok about 2 weeks ago the slave cylinder went on the clio so i got i towed into jms tuning were james and tom were going to work onit there they put a new clutch and slave cylinder in and also done other modifactions like take the pre-cat off and match up the inlets once that was done they remaped it aswell. After 2 weeks its all done but now ive got all the lights up on the dash abs and traction control they have followed there routes back and checked all the connections and cant find anythink but they said if you wait till monday they can get this thing to plug into the car and should show were the fault is but i need the car for the next few days does anyone no what it could be or had the same problem as this??? Thanks james