recently acquired used f350 diesel pick up, 2003. had upgrades already, such as ram air, performance chip, unknown tranny upgrade, engine stud kit, stainless wide exhaust. noticed after driving a day or so that tow haul light was flashing. diesel mechanic friend checked code and sd torque conv. prob., subbed job to tranny shop where rebuilt torque conv. light was off when i got it back, but after about 5 mile of driving light came on again. sent truck back to tranny shop, chnged some pressure solenoids in tranny. light still came on. any one have any experience in this prob? running out of ideas. by the way, have about 85000 miles.also tranny did not seem to slip initially, and still not slipping

 

What are the DTC's?

 

does it shift "really" firm ??? like put ur back into the seat firm i mean..
the tranny does this "fail-safe mode" to avoid u burning the tranny up by it not shifting, if it sences a problem..

i had my 99 SD250 auto-box have the tranny ecm go bad.. Ford at first thought it was the overdrive shift solenoid.. but after changing it, the problem came rite back a few days later..

then they tried replacing wiring.. still no fix...

according to the Ford service manual the ECM should have been fine cuz it was returning codes, but in the end they put a different one in and the problem fixed..

so it jsut went to show that even having a game plan doesnt always work..

i'd consider having ur Ford dealership have a look at it.. hope ur issues dont go as far into $$$ repair bill mine did..

 

thanks for the quick response! my first diesel truck and i know nothing about them. as far as i no the code had something to do with the torque converter, so i was told. i dont know what they changed in the tranny the second time it went in, i will find out tmrw. from all the posts i've been reading it sounds alot like the shift solenoid. any other infor would be greatly appreciated. thanks! also, the light does reset itself every time the truck is shut off, and there doesnt seem to be any set pattern or reason for it to come on. the truck seems to shift and drive fine.

 

mine also had the OD/shift lite flicker on or off for a few weeks before it finaly started shifting hard all the time and the flashing lite stayed on after that till i got it reparied..

GL with the fix...

 

usually if the o/d light flashes, the trans is trashed or... if you have a E4OD (no bolted on, removable plate on the either side of the transmission case about middle) it could be the manual-lever-position-sensor has crapped out. i have a 94 non power-stroke factor turbo IDI that this happened to. i made it from western VA to indiana until it would go no further. it was able to screw with the linkage and make it the 400mi back to winchester VA. ruined my hunting trip, but it didnt cost my a trans... have a reputable "mom and pop" trans shop check it out. they seem to be the most unbiased... dealer is about 5 grand. ammco is bout the same...

 

A bad trans temp sensor will cause Tow/haul light to flash too.

 

went to mechanic with all this info, and found all three shift solenoids were changed already. said they were going to flash the computer because tranny had extra work done originally. not the vss diff lock either because changed the abs sensor/solenoid? too. could this truck be anymore complicated? thanks to all for arming me with info, will keep you posted.