Recreational Vehicle Lpg Tank Valve/gauge problems of the 2009 Dodge Charger

I own a 2009 Dodge Charger. When cranking engine all the check lights came on (including engine, coolant, tire check, etc. ). The tempature gauge was also all the way cold. I cut the engine off. The engine was slow to crank but did crank. I drove not even a half mile and the temp guage was going from cold to hot and then the engine stopped. When I opened the hood I found my car was smoking and the coolant was almost bone dry. Prior to this incident no check lights have appeared. I took my car to landers Dodge in southaven, ms they ran a check and preformed maintance to my car and added coolant. Now, a month and half later my car is smoking again and coolant is extremely low. While my car is smoking and almost no coolant, temp gauge is not detecting my car running hot. I believe my sensors are not working correctly and have a faulty coolant container. Thanks!.