Theory of Operation

WARNING: This page is about a different car, the 2011 RAM Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.

The Diesel Exhaust Fluid (DEF) system holds a total of eight gallons of fluid. There are a series of three warning levels to indicate to the customer when the fluid is low or incorrect. The driver warning and inducement strategy for a low fluid condition is as follows: The first warning will occur when the tank level is at approximately three gallons. The customer will here a chime and get an EVIC message reading "LOW DEF REFILL SOON". The second warning level will occur when the tank level is at approximately two gallons. The customer will here a chime and get an EVIC message reading "REFILL DEF ENGINE WILL NOT RESTART IN XXX MILES". If the message is ignored until the tank is empty, the vehicle will not start. The customer will here a chime and get an EVIC message reading "REFILL DEF ENGINE WILL NOT START". The system will arrive at this level with approximately 0.7 gallon of fluid left in the tank. The vehicle will not start until a minimum of two and a half gallons of approved Diesel Exhaust Fluid is added to the tank .