First let me say hi, have read here plenty but just registered . I have a 2000 Dodge with a auto. Had it rebuilt a couple of months ago . My truck would drop into neutral if you slowed down . For example if you were coming to a yield sign. My nephew has a trans shop and he built it for the cost of parts so it didn't cost me a lot of money to build. My problem now is ( and they are having a hard time figuring it out). It shifts crazy at times and times it just fine. Trans has been pulled and went thru to make sure something didn't go wrong with the build . We put new parts , torque converter, PCM, and valve body with a shift kit . I have read about the O D problem but my truck will do this in the lower gears as well . Its like it cant make up its mind if it need to be in second or third. Then when it shifts again same problem . IF you accelerate hard it will shift just fine. They think it may be some kind of electrical issue . I don't know , He wanted me to put a new apps sensor on but before I start throwing parts at it I thought I would do a little research and see what you guys think. Thanks in advance , Mike

As for the weird shifting and lock and unlock issues I would bench test the alternator and batteries first thing. Then go forward from there. I rather replace or repair something simple than replacing high dollar parts on a guess.

Gonna add my $0.02 here (and it is really only worth what you paid for it....) Sorry just not an auto guy.If it is not the wiring/grounding/voltage problem like Mike was saying, these symptoms also sound like the shift solenoid problems. So you may want to research that. (hmmm wonder if the shift solenoid problem is voltage related...)GLHag

Haggar bring another good point up it wouldn't be a bad idea to check error codes.