2021 Ram 3500 Cummins HO. Crazy malfunctions

[Capt.Salty.Beard]

I have a 2021 Ram 3500 Cummins.
All the sudden. A few weeks ago, I was driving 65mph and the dash lit up with warnings, message said "service 4wd system", check engine light came on, and then it slammed down into 1st gear (scary while driving that fast). When put in Park, the "P" blinks and message says "Vehicle Not in park".

Dealership technicians are stumped. It drives, but accelerates extremely slowly. I have a 7 month old truck, but have to put my flashers on as I accelerate to let drivers know I'm slow.

Any ideas. Some think maybe it's a security system thing. But I can't find anything matching symptoms when looking at issues caused by KARR security system.

 

[dslbrnr]

Has water entered the engine bay, cleaning etc?
Check and clean all the electrical connections having anything to do with the powertrain. Either spray silicone or apply dielectric grease when reconnecting the electrical connections.
Also look for damaged wire looms or connections.
Good luck, hope you get it figured out

 

[elephantrider]

check that all fuses are properly seated.

 

[gimmie11s]

check that all fuses are properly seated.

This. Get into the engine bay and ensure all fuses and relays are FULLY seated. Common problem on these trucks for some reason.

 

[Firebird]

No specific help for you on your HO, but when I worked for Volvo, we had a lot of issues in people’s cars who had aftermarket alarm systems installed.