Diesel Exhaust Fluid - RAM 2500 2020 Quick Reference Manual

At cold ambient temperatures, it is recom-
mended to warm up the vehicle by idling the
engine before driving. Engine speed and
torque will be limited at low ambient
temperature and low coolant temperature as
part of the Engine Warm Up Controls
Strategy. Use of a block heater and winter oil
(5W-40) in cold ambient conditions will
reduce time needed to achieve full engine
operation.
Fuel Economy
Diesel engines offer superb fuel economy
under certain conditions. Fuel economy
should improve after the vehicle is broke in.
Many factors will affect or reduce fuel
economy.
• After-treatment Regeneration
• Cold Temperatures
• Wind
• Extended Idling
• Towing
• Short Trips
• Fuel Quality
• City Driving
• Aftermarket Grills
• Oversized Tires
• Gear Ratios
If at any time your check engine light is on,
please visit an authorized dealer.
RAM 2500/3500

DIESEL EXHAUST FLUID

Your truck is equipped with a Selective Cata-
lytic Reduction (SCR) exhaust emissions
after-treatment system. This technology is
used to reduce Nitrogen Oxides (NOx) emis-
sions of the engine so that it meets current
U.S. EPA and California exhaust emissions
requirements. This system is new to many
truck operators and does require some main-
tenance for proper operation.
In order to function properly and ensure the
vehicle meets applicable emissions stan-
dards, the SCR system injects Diesel
Exhaust Fluid (DEF) into the exhaust
upstream of the SCR catalyst. The DEF
reacts with the exhaust gas inside the cata-
lyst to convert NOx to harmless gasses prior
to release into the atmosphere.
DEF consumption varies with vehicle use
and duty cycle in much the same way as
diesel fuel. Since it is consumed during
operation of the vehicle, the DEF tank must
be refilled periodically when indicated by the
DEF gauge and warning messages. The blue
filler cap is clearly marked "Diesel Exhaust
Fluid". On Chassis Cab trucks, it is located
behind the cab on the driver's side of the
truck. On Pickup trucks, the blue filler cap is
located inside the fuel filler door. When
refilling the DEF tank, make sure the fluid
used carries the API certification logo for
Diesel Exhaust Fluid.
Low DEF Warning
When the DEF level is low, a message
stating "Low DEF Refill Soon" will be
displayed in the instrument cluster, the
"Low DEF" Icon will illuminate, and a
chime will sound. Unless DEF is added, a
mileage countdown will be indicated with
the message "Speed Limited to 5 MPH in
200 Miles - Refill DEF". This message will
be updated and displayed at each startup.
When the countdown reaches 100 miles
(160 km), the message will remain on the