i have a '99 3500- 5.9l cummins- 107,000 miles. the other day i was leaving the driveway and the truck shifted up to second and wouldn't go any higher (max 20mph). I tried going down the road, increasing the rpm's and lowering it, but the tranny wouldn't shift. I've been looking around and asking around and what i hear is it might by the transmission control soleniod. does that sound right? or would it be the control sensor? any help would be appreciated.

 

Its the Governor Pressure Solenoid maybe. You can take it to a transmission shop and have them do a read on the trans.

Here is a kit that works well. Dodge Heavy Duty Master Solenoid Kit

 

thanks... I ended up replacing the Control solenoid which didn't do the trick at first. I needed to reset the pcm, then the truck would shift properly.