RAM 2500 shifting up limited to 3rd gear

[RAM2500LGT]

While towing a 5th wheel (9800lb) behind my 2021 2500 Cummins, I encountered a strange behavior. Was going down a 6% grade in 3rd gear at 30mph. I wanted to use exhaust braking so I selected the FULL exhaust braking mode. It did not activate. I had foot off of throttle. I decided to select 4th gear and to my surprise transmission would not go higher than 3rd! I finished the hill in 3rd and pulled off road. I shut off truck and restarted. Gear selection worked ok after that.

 

[jejb]

You can't select 4th gear. All you can do is limit the tranny to not shifting above 4th, in this case. The truck is going to do what it thinks it needs to do to try and keep you at 30mph going down a 6% grade. But once you got to the bottom and increased speed, it should have shifted into higher gears.

 

[mtnrider]

Exhaust brake will not activate unless the converter is locked and it is above a certain mph and RPM. Also will not upshift until certain parameters are met.... Normal, nothing wrong with your truck.

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