Theory Of Operation

WARNING: This page is about a different car, the 2013 RAM 3500 HD and 2013 RAM 2500 HD. 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 5.7 gallons of fluid on a regular cab and 9.2 gallons of fluid on a chassis cab vehicle. 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 two gallons. The customer will hear a chime and get an EVIC message reading "DEF Low REFILL Soon". The second warning level will occur when the tank level is at approximately 1.5 gallons. The customer will hear a chime and get an EVIC message reading "Speed Limited to 5 mph in XXX MILES Refill DEF". The customer will hear a chime and get an EVIC message reading "5 mph Max Speed Refill DEF". The system will arrive at this level with approximately 0.7 gallon of fluid left in the tank. A minimum of two and a half gallons of approved Diesel Exhaust Fluid is added to the tank to eliminate the 5mph derate. .