I have a 2005 4wd 2500 with automatic. It is bone stock. It has 101k miles on it. i got it in Florida and drove it home to north ga with no problems. Then the other night, I noticed when taking off, it wasn't in 1st gear. I stopped and started off several times. I thought it was taking off in 2nd, but its 3rd. It shifts one time, then locks up. I am thinking it is something electrical. I have heard that the ground in the pcm can go bad and cause this. Any ideas of what it may be? It was raining the night it started doing this. It just occured to me that maybe the connection got some water in it. Guess I'll check that tomorrow.

 

Most times it has to do with the governor pressure transducer or solenoid. Check for codes. Turn the key from off to on 3 times ending in the on position ( not cranking). Codes will read in the odometer screen.

 

Mine was acting similar. Codes showed up. It was the gov. pressure selonoid and gov. pressure sensor. It's easy to fix yourself if that is the problem.

 

Yep, sounds like the t/ducer. Seen that before. Let's see....one, two, three of my trucks, one twice.

Chris

 

There are no codes. I haven't checked the connections yet for moisture either. I will do that today.

 

Could the trans be overfilled? After i was messing with mine one day I acidentilly overfilled it by a few quarts and it would only start in third.