I own a 2001 Dodge 2500 with the 5.9L Cummins. I have a stock automatic transmission that has always been treated well. I have performed regular services on my tranny every 30,000 miles and my truck now has 167,000 miles on it. The problem occurs at shift points between 3rd and 4th gear around 30 mph and at 45-50mph. With my foot lightly depressing the pedal it seems that the tranny wont shift and the engine revs up and down between 1500 and 1700 RPM. If i depress the throttle with more force the engine revs up just fine and the transmission seems to shift properly. The problem only occurs when trying to hold a particular speed (30mph and 45-50mph) with the throttle held around 15%. The transmission keeps trying to shift but wont make the shift until i apply more throttle. I just noticed the problem about a week ago so I checked fluid levels which were within spec. I am a diesel mechanic for Detroit Diesel but I have not had a lot of experience with Dodge automatic trannys. Please help!

 

Could it be the APPS/throttle position sensor? My 94 had a similiar issue with shifting. Where the throttle shaft went onto the socket on the TPS, it had worn from use, and was not sending a true throttle position signal to the transmission. I replaced that, and all was good again.

 

Try resetting your apps, after cleaning the battery connections.

 

Does anyone know where I can purchase a new APPS? I have called all the local parts stores and no one seems to know what the heck I am talking about. I can only find a TPS for a manual...