transmission only has 30k miles on it, heavy duty torque converter from circle-D

last night I was driving on the highway (in Drive) and going up a hill it all of a sudden the engine just rev'ed up- as if it was in neutral. I had to pull off the highway, when I was stopped I put it back into part and moved it back to Drive and it was able to move, but as I applied more gas it started slipping


If I drop it down to 1st or 2nd gear, it works fine, no slipping at all. when in 3rd or 4th it seems like it stays in 1st gear

transmission fluid was nice cherry red at a full level. No leaking or any distruction under the car

any tips????? I haven't have a chance to check it out, might be a wiring problem???

 

So if its in D, what happens when you take off? What shifts does it not make?

 

if you take off in D, it just stays in 1st gear- and slips a little and if you let off the gas and get back on it it basicly acts like it's in neutral

when I manually put it in 1st gear, it runs fine
when I manually put it in 2nd gear, it runs in 2nd gear fine

Drive doesnt shift out of 1st gear at all, neither does 3rd gear from a stop

 

plugged an obd2 up to it while driving, speed sensor isn't giving any signal which is most def. causing the problem

 

I am having the same problem, when in D or OD it will run 1st and 2nd and when trying to go into 3rd it will just rev.. I think its an internal job I doubt its the solenoid, im not getting any readings on it when I plug in the OBD II

 

well it wasnt throwing a code on mine, with a 'better than autozone employee' scanner you can actually see the data that the PCM is receiving, such as IAT, coolant temp, speed, rpm, Throttle %, etc. So I was able to see that as I was driving 20mph on the dash, the speed the PCM was getting was 0mph

BUT, I did a conversion (its not a f-body, got a ls1 in a jeep) so I have 2 seperate speed sensors. One controls my gauge speedometer(which is still working) and the other sensor is a GM sensor that sends the signal pulses to the ls1 pcm(which is now NOT working)

so if this problem was happening on yours, your gauges speedometer would not be working