I’ve had no overdrive since I’ve bought the truck. I’ve replaced trans fluid, overdrive/tcc solenoid, tps sensor, checked throttle valve cable and have been trying to find trans temp sensor but not sure if my truck came with one. Is there anything else I can try or anything I can bypass for overdrive to work. It shifts and downshifts perfect in all other gears.

 

Quite likely there is no trans temp sensor on yours. Is the Trans Temp lite on?? What about the O/D off switch?

 

No there is no trans temp light on the dash and the button works.
Also the torque converter is working and locking up normally

 

Light off = OD on
Light on = OD off.

 

Yeah it works fine
I’ve tried unplugging it and that didn’t do anything so I plugged it back in

 

All it does is send a momentary signal to the PCM. The PCM turns on the little light.

What RPM is the engine turning at 55 mph?

 

2500-2600

 

Ok, yeah. That's too high.

Does anything change when you disable O/D?