I own a T Reg. Fiat Duccato 1.9 Torbo Diesel and the Key Code light came on and even the AA could not fix it, so they towed me to a Fiat Main Dealer who did fix it and charged me £230.00. One month later it came on again and like before would not go out. In desperation and not wanting to pay out again I inspected nearly every wire and connection on the vehicle. I found a trip switch inside the Engine compartment right next to the Possative Connection of the battery. It is a round rubber encased switch and when pressed resets the key code light, to my great delight and relief.
Philg4649
Philg4649