Hello all , my name is ely i have a ram 3500 dually 2015 diesel with 48000 miles, today i got q message 5 mphmax speed service def system see dealer , my def tank is almost full , i dont want to go the dealer so they can charge an arm and leg for something simple , can anybody help me , any inputs really appreciate, I disconnected the battery and restarted by same message keep coming up.
Thanks in advance for all your help