RAM 2500 2021 Owner's Manual page 236

234 STARTING AND OPERATING
DEF Fill Procedure
NOTE:
For the correct fluid type Ú page 481.
Remove cap from DEF tank (located on drivers
side of the vehicle or in fuel door).
Fill Locations
1 — Diesel Exhaust Fluid (DEF) Fill Location
2 — Diesel Fuel Fill Location
NOTE:
The DEF gauge may take up to five seconds

to update after adding a gallon or more of
Diesel Exhaust Fluid (DEF) to the DEF tank. If
you have a fault related to the DEF system,
the gauge may not update to the new level.
See an authorized dealer for service.
The DEF gauge may also not immediately

update after a refill if the temperature of the
DEF fluid is below 12°F (-11°C). The DEF
tank heater will possibly warm up the DEF
fluid and allow the gauge to update after a
period of run time. Under very cold condi-
tions, it is possible that the gauge may not
reflect the new fill level for several drives.
At 40°F (4°C) you could see some increase

in the DEF gauge due to the tank thawing.
The gauge and level sensor are working prop-
erly and is just updating with proper thawed
DEF.
Excessive overfilling of the DEF tank can

result in a MIL lamp/fault code and inaccu-
rate level readings.
Refilling With Nozzles
You can fill up at any DEF distributor.
Proceed as follows:
Insert the DEF nozzle in the filler, start

refilling and stop refilling at the first shut-off
(the shut-off indicates that the DEF tank is
full). DO NOT proceed with the refilling, to
prevent spillage of DEF.
Extract the nozzle.

Refilling With Containers
Proceed as follows:
Check the expiration date.

Read the advice for use on the label before

pouring the content of the bottle into the DEF
tank.
After the indication appears on the instru-

ment panel display Ú page 111 fill the DEF
tank with no more than 4 Gallons (15 liters).
CAUTION!
To avoid DEF spillage, and possible

damage to the DEF tank from overfilling, do
not "top off" the DEF tank after filling.
DO NOT OVERFILL. DEF will freeze below

12ºF (-11ºC). The DEF system is designed
to work in temperatures below the DEF
freezing point, however, if the tank is over-
filled and freezes, the system could be
damaged.
When DEF is spilled, clean the area imme-

diately with water and use an absorbent
material to soak up the spills on the ground.
(Continued)