Trans temp sensor problem?
 

'04-F250-6.0-85k. After warming up and driving about 15 miles the trans temp gauge will slowly rise like normal but then slowly go back down. After that the check gauges light with come on, and after about another 2-3 miles the tow/haul light will start flashing. The trans seems to work ok, the level is perfect, and it doesn't smell burt at all. After the truck completely cools down (overnight) it will work fine for another 10-15 miles and act up the same way again.

I am guessing a sensor problem but does anyone have any other ideas? I am probably going to have to take this to the dealer as it is probably over my head. Do you think it is an expensive fix?

Also, sorry if this has already been talked about, I attempted to search first but really didn't find anything like what this truck is doing.

THANKS!

Put a scanner on the OBDII and pull the codes once it start. This will be a place to start once we know the DTC's.

I have the same problem and it dont give DTC code at all !!

When the tow/haul light flashes a code is stored in the PCM's memory. Many scan tools can't read Ford trans codes, but the code is there. You need a Ford specific scan tool to get it.

I'm having the same problem now.... anyone have this resolved or know what causes this? Is it just the trans sensor that went bad? How hard is it to swap it out? Any help is greatly appreciated!

In many, many past posts this problem has been the TFT sensor in the tranny. It is a temp. sensor. If the tranny is working good and the temp. is all over the chart or just going high and it has had regiular service, the TFT is the odds on culprit. Perhaps a tech would like to comment. From past posts it is not that difficult to change and not that expensive.

It's a 1 to 1.5 hour job changing the TFT sensor out. List price is around $70 and you don't need a internal filter or pan gasket. The end of the TFT sensor that plugs into the trans is T shaped with a O ring on it, so once you disconnect the wire terminal from it you turn it 90 degrees and pull it out grabbing it with a pair of needle nose pliers.