I have a 95 CTD with an auto as the weather in MN has ben getting colder i have noticed that my trany temp light has ben comming on at startup. it usally goes off after a few miles the owners manual says tis light is for overheating. now it wont go off at all and when it is on i cant get overdrive or lockup. i have had this truck for the last 7 years and put several thousand miles on it and i have never had this light on that i can rember. i have check fluids and it is full there seems to be no slipage in the trany.any ideas what is causing this or how to fix it

 

Check the sensor wiring, my truck had frayed wiring, cut it out replaced, no more problem. The other possibility is a dead sensor, given the trucks age it wouldn't be a big surprise.

 

i have checked all wireing unpluged all conectord cleaned grounds and the problem is solved