my son has a 99 ram 4x4 with a 5.9 . It didn't shift out of 1st gear.We replaced the govenor selenoid and sensor,and it still did not shift. When we reset the computer it shifts fine. When you start the truck again it won't shift. Every time we reset the computer it shifts fine . I'm baffled on what to try next,does anybody have any suggestions?

 

Where did you get your sensor/solenoid? These trucks don't seem to like aftermarket parts very well..... especially the assorted sensors.

While you were in there, did you adjust the bands?

 

Really sounds like the governor sensor and solenoid... did you get MOPAR parts?

 

Could be the output shaft speed sensor.

 

not positive, but didnt they do away with those after '97?

 

I also replaced the pressure switch and solenoid along with a new speed sensor. I finally traced the problem to a ground fault with a oxygen sensor that shares a common ground with the solenoid. to test this just unplug one o2 sensor then test drive it if it doesnt work plug it back in and try the next one. I replaced the suspect o2 sensor and mine shifts like new again. make sure you clear any codes after its fixed. good luck