We own a 2005 3500 2wd crew cab dually/Cummins that is used to pull a 40' gooseneck racecar trailer. Has been a great truck except for below which started last year.
Having an issue when it's warm outside or pulling against wind. The temp gauge will peg hot and engine will begin to shut down. Pop the hood, not hot and if you check with an infra red temp gauge it's actually very cool, where it needs to be. We unplug the temp sensor (of course temp gauge doesn't work) and we travel on with no issues.
Dealers can't replicate problem and no codes show up.
Can't run without a temp gauge if something would happen plus there's no air cond. without the gauge working.
Any help would be greatly appreciated!!

 

Replace temp sensor. Sounds like it's giving bad info to the PCM.

 

Thanks p38251.
Just talked with our dealer. Said it was the obvious choice, but there were no codes. They want to look a little farther and then change it out.
Not too hot here yet, so there's a little time. "Winter" doesn't want to end...also making it tough on the dirt tracks.

 

Got the temp sensor but didn't realize it was changed out last fall to correct the issue. Obviously it didn't fix then, so took sensor back. Dealer is still researching what to do.
Used truck this weekend in what we can call "heat"(mid 80's) for this spring and it acted normal and that's the problem. UGH.

 

Are there any outstanding TSB's? The dealer should be able to tell you if there are any re-flashes available.

 

I recall there being a problem with shorting wires on the harness by the AC compressor. I dont remember what the problem was that the short was causing, sorry. It is worth a look though. What your seeing sounds to me like an short. When you pull the sensor connector the gauge reads cold right? Maybe measure the connector to see if there is a short.

 

steve05....the temp gauge actually pegs on the hot side.
Haven't taken truck back to dealer as they are still trying to decide what to do. As always running fine, but no ac w/temp gauge pegged hot.
Thanks for all the info, I pass it on to the dealer.

 

My temp gauge was showing a high temp that didn't seem accurate. My scan gauge showed it ran consistently at 191, unless towing or pulling a long hill. I left it attached, sovi can press a button and check. But new OBD sensors are Bluetooth and can show the info on your phone.