xs traction control

Hi, the traction control light on my td5 (05) comes on when I accelerate, flickers when cruising and goes off when decelerating. Both the traction control and ABS are working fine and two diagnostic checks by independant garages show no faults. One garage phoned a main agent on my behalf for advice and they had little idea other than replace everything. I have tried cleaning most of the connections with no success but as the MOT looms nearer I really need some help as to how to proceed. any help would be much appreciated.