My RAM, a 2012 with the 6.7, Megacab about 15K miles, check engine lite came on yesterday with normal highway driving. Took it to autozone for a quick scan, code P026A, Charge Air. What is this, how serious is it. I have an appointment with the dealer for saturday morning to check it out. Can I drive the truck.

Also the truck does have a plow on it, don't know if that has anythng to do with it.

Thanks

 

Charge air cooler efficiency below threshold
I don't have the diagnostics for your MY but it sounds like a bad sensor or something not allowing the cooler to do its job, like a winter front cover or plow...
I can't imagine in a cold climate that the plow would restrict that much air flow unless you have a cover on also.