Torque converter not locking up.
#14
Yeah, the high rpm at cruising speed, and only the minor drop with the O/D off button..... But, the PCM should whine about not seeing its RPM drop when it commands Overdrive...... unless, for some reason, it ISN'T actually commanding it.... If the PCM thinks trans temp is too high, it will disable O/D even before the Trans Temp light in the dash comes on. But, that also should turn the O/D off lite on. I think the trick would be, wire a lite in parallel with the O/D solenoid circuit, and see if the light even comes on.
#15
#17
See if the PCM is actually commanding O/D, as listed above. If you have a scanner than can read live data, see if it will tell you what it thinks trans temp is. Also see what voltage the trans is actually getting. Keep in mind, the trans only gets power for a few seconds at initial key on, after that, only if the PCM sees the engine running.
#18
I checked to see if it had power to transmission. And it does. Gave all the connections a once over. Drove it again did the same thing to start with. Shifted it into natural then back into drive everything started working. Shut truck off drove agian everything is working. Don't understand it really. Had one little spot to where you I've it enough throttle to knock down it didn't want to shift again for a few seconds then it work
#19