Took the vehicle for an oil change at the dealership and they did a vehicle inspection as well. The service 4 wheel drive light had been popping up on the dash as well as a message 4 wheel drive system unavailable. They said the rear differential or ptu had to be replaced and would cost 5 grand. Took it to a mechanic and he also said the ptu was bad and is coming up with a qoute for me as well.