RAM 1500 2017 Quick Reference Manual - page 15
Adding Diesel Exhaust Fluid (DEF)
The DEF gauge (located in the instrument cluster) will display the level
of DEF remaining in the tank.
Completely fill the DEF tank through the diesel exhaust fluid fill
location at every maintenance interval, or before if prompted by the
instrument cluster display.
The DEF tank on these vehicles is designed with a large amount of full
reserve. So, the level sensor will indicate a full reading even before the
tank is completely full. To put it another way, there’s additional storage
capacity in the tank above the Full mark that’s not represented in the
gauge. You may not see any movement in the reading – even after
driving up to 2,000 miles in some cases.
NOTE:
• Driving conditions (altitude, vehicle speed, load, etc.) will effect the
amount of DEF that is used in your vehicle.
• Another factor is that outside temperature can affect DEF consump-
tion. In cold conditions – 12° F (-11° C) and below – the DEF gauge
needle can stay on a fixed position and may not move for extended
periods of time. This is a normal function of the system.
• Since DEF will begin to freeze at 12°F (-11°C), your vehicle is
equipped with an automatic DEF heating system. This allows the
DEF injection system to operate properly at temperatures below
12°F (-11°C). If your vehicle is not in operation for an extended
period of time with temperatures below 12°F (-11°C), the DEF in the
tank may freeze. If the tank is overfilled and freezes, it could be
damaged. Therefore, do not overfill the DEF tank. Extra care should
be taken when filling with portable containers to avoid overfilling.
Note the level of the DEF gauge in your instrument cluster. On
pickup applications, you may safely add a maximum of 2 gallons
(7.5 liters) of DEF from portable containers when your DEF gauge is
reading ½ full. On Chassis Cab applications, a maximum of 2 gal-
lons (7.5 liters) may be added when the DEF gauge is reading ¾ full.
• There is an electric heater inside the DEF tank that automatically
works when necessary. And if the DEF supply does freeze, the truck
will operate normally until it thaws.
• Ensure the DEF cap is reinstalled prior to filling vehicle with diesel
fuel to avoid spilling diesel fuel into the DEF Filler.
R A M 2 5 0 0 / 3 5 0 0