freelander hdc prob

Hi I know you guys on here don't rate freelanders but hope you can help with this. I have got a 2001 my td4 auto for the Mrs, bought private ,doesn't look as if it has ever been off the road, and I suppose the largest hill it is ever going to descend is the slope into tescos carpark, so this is not a matter of life and death but the hdc doesn't appear to be working . Engine , gearbox, brakes and abs are all working perfect and the hdc lights in the dash light up when the ignition is switched on and then go off as they should, but according to the manual they are supposed to flash when the button is pressed and in first gear or reverse and also the button should light up, this does not happen . Before I ask a dealer and he tells me I need a new computer or something at a colossal amount of money, I would be grateful if someone could shed some light on the problem as I must confess I am at a loss on the subject. Anything to do with mole grips and a bamford spanner I am ok but all this electric stuff is beyond me. Thanks in advance Charlie