I have a 99 24v 2500 2wd  Mostly happens when truck warmed up' It will drop out of OD and sometimes then drop to 2nd. I have dome all the cleaning up etc. I have fresh pink fluid no slipping just wont stay in od mostly. A funny thing is when it does this if you set the cruise it will take off running faster.Trans was rebuilt according to previous owner but don't know who. I have been told that the shifts are controlled by electric in trans. Have not but do intend to replace VSS, but got a feeling it is more then that.  Thank you for any help  [i do have a new alternator on way for lock/unlock problem.

Could this be as simple as some bad grounding?  Others will hopefully chime in & add to this.

 

 Do the simple inexpensive steps first anyway. Should test even a new Alternator. Battery clamps and posts clean, good batteries.etc.

 

I remember reading about changing some of the trans sensors over to Borg Warner too.

 

How many miles on it?

3 & 4 are electrically controlled. 1 and 2 are mechanical. I'm no expert but maybe the governer pressure solenoid as it seems to be a weak link for some

All ready did all grounds clamps any wire I could get too,even power contol modual wiring and grounds,have not done anything with trans wires from under truck ty for replys,again I keep seeing stuff about solenoids in trans pan

ECM, PCM and VP44 are on the Passenger side negative battery cable. There is no body grounds for these 3 computers.

 

Any error codes? Yes error codes can exist without tripping a check engine light.

 

Any programmers on the truck previously?

If the governor solenoid and pressure transducer have never been replaced as far as you know or it's the original trans, it's time to replace them. They're almost wear items in a dodge. It's a good starting point for not a huge cost, and new fluid obviously. You can by these parts individually, borg warner solenoid, pressure transducer and 3-4 spring. Make sure they're for a 99'. Can't say for certain they'll solve everything, but when I got my truck, all I had was 1st, 2nd and sometimes 3rd. When it warmed up, all I had was 1st and 2nd. See link

 

http://www.cascadetransmissionparts.com/47regovernorpressureservicekit9899.aspx

yes on neg cable extra clean.  when I got the truck it had a broken ob2 connector[under dash] it has a replacement exhaust with straight thru, no muffle etc looks like 5 inch. with busted connector I suspect it had a programmer or some thing. Have checked codes only code is the one for too much boost got a junk yard connector and using Your wiring diagram replaced it. [thank you for posting that] That link and kit is probably how I will go.there is a wire from edge of pcm? next to air cleaner and it goes to a block ground, cleaned it I spent almost 8 hours on cleaning wires, and all connectors. Truck was used to travel the country picking up old/ antique motorcycles on a 20 ft trailer. Looks like good care but think trans, and a ps gearbox going out made the guy trade it to his friends motorcycle shop for a newer truck.