heating Ram 1500 2017 Diesel Supplement

4. Reinstall cap onto DEF tank.
Filling The Def Tank In Cold Climates
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 tempera-
tures 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.
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.
The difference this makes varies by vehicle. Heavy-duty
pickup trucks have a 5.7-gallon (21.5 liter) tank that will
display a Full reading when about 90 percent full. This
means that drivers can consume at least 10 percent of a
truly full DEF tank without seeing any visible change in the
gauge reading. Chassis cabs have a larger 9-gallon (34 liter)
tank, and will display a Full reading when about 75 percentfull. So drivers can consume 25 percent of a truly full DEF
tank without seeing any visible change in the gauge
reading.
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 gallons (7.5 liters) may be added when the DEF gauge is
reading ¾ full.
DIESEL EXHAUST FLUID
Your vehicle is equipped with a Selective Catalytic Reduc-
tion system to meet the very stringent diesel emissions
standards required by the Environmental Protection
Agency.
The purpose of the SCR system is to reduce levels of NOx
(oxides of nitrogen emitted from engines) that are harmful
to our health and the environment to a near-zero level.
Small quantities of Diesel Exhaust Fluid (DEF) is injected
into the exhaust upstream of a catalyst where, when
vaporized, it converts smog-forming nitrogen oxides
(NOx) into harmless nitrogen (N2) and water vapor (H2O),
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