One problem related to check engine light on has been reported for the 2009 Dodge Ram 2500. The most recently reported issues are listed below.
A few weeks ago my check engine light came on. Advance auto parts said an error code for the turbo charger was present. I have 43900 miles on the engine. Dealer told me it was not critical and I made an appt. Before bringing it back, a new code stated dpf filter full 100%. Brought it to the dealer and was told the dpf needed regeneration and would cost $150+. New trucks give warnings of 25%/50%/100% and "change driving habits". Apparently diesels shouldn't be driven in town w/overdrive. Instead we need to pull heavy loads. The only option: drive on the highway in 4th gear to bring rpms to at least 2500 rpm every so often! plus, the turbo charger apparently was clogged because I don't use the diesel automatic deceleration brake when not pulling a trailer. The dealer had to order some type of additive to clean the turbo charger and they did 3 cleanings with 3 cans of cleaner on a machine to let the engine run. The manager didn't charge me to do the cleaning since they were inter-related and happened together. Otherwise, there would have been another diagnostic charge and cleaning charge that took two hours to do. I asked if Dodge was planning an upgrade to the onboard computer to provide those pre-warnings for the dpf filter. The svc mgr said no. Why not? from all I read, if the dpf filters gets to 100% it can damage the system. To replace the dpf, it and the catalytic converter would need to be replaced at a cost in the $5-6000! so, the only option is to periodically have them check the status using a diagnostic at a cost of $95 but likely, would not show anything until it gets to 100% full. This is ridiculous since they should be able to do a program upgrade to warn about the dpf filter as well as the turbocharger levels of soot. I bought the truck to pull an RV and only pull it every 6 months or so. Why pay $45,000 for a truck if you can't drive it around town.