I think its 2nd gear because I can hit 40-45 mph, but my neon won't shift gears. It also shifts hard into reverse and 2nd but didn't until problem started. Tranny was rebuilt by dealer a few years ago. While stopping for a red light the car stalled and it started right back up but now won't shift. I really could use some wisedom here, thanks much.

 

This is an automatic trans.?

It's called "Limp mode." Most likely you have an electrical error, or a problem with the speed input sensor, and your car is putting your transmission in time-out. Probably a (relatively) cheap fix.

 

thanks for the info. is the sensor easy to get to? what is the best way to approach it? from the engine compartment or under the car? can you let me know a specific location please? thanks again.

 

Get a code reader and check the codes. Don't guess when you can know for sure. Yes, speed sensors are common, but there are plenty of other things that can and do happen to cause the limp-in mode. Mine for example was loss of prime and gear error codes for every gear. Needed a new oil pump.

 

By the way, if you can't get a code reader, i learned here that you can put the key in and turn it from off to on (not start) 3 times, and leave it in ON the 3rd time, your error codes will display where your mileage usually is. be ready to write them down.

 

The only caveat to that is that if there are transmissions codes, only the P0700 will show up to let you know that there are stored codes. You need a reader for transmission codes.

 

I had a similar problem with my neon when the battery light was on. Thanks to darthroush i learned that it was the Battery Temp Sensor. It was killing the battery and alternator. once that battery was almost dead it would go into limp mode.

I don't know if any of that is really related or not but since the sensor was replaced we haven't had a problem.