There are 3 temp sensors on these machines, check the resistance on these sensors first the information is in the service manual, if that tests good then check the continuity for the wires up your composit instrument quite easy to do, on our machine that all tested good and it turned out to be the composit instrument itself 1100.00 dollars Canadian dollars, our machine also was in limp mode with the fan on all the time but you should get the codes first.