2012 Ram 5500 Chassis Cab sensor

CAUTION!
The TPMS has been optimized for the original
equipment tires and wheels. TPMS pressures and
warning have been established for the tire size
equipped on your vehicle. Undesirable system opera-
tion or sensor damage may result when using re-
placement equipment that is not of the same size,
type, and/or style. Aftermarket wheels can cause
sensor damage. Do not use tire sealant from a can, or
balance beads if your vehicle is equipped with a
TPMS, as damage to the sensors may result.
NOTE: The TPMS telltale is also accompanied by a
“Low Tire” message in the Electronic Vehicle Information
Center (EVIC) screen. Refer to “Starting and Operating/
Tire Pressure Monitor System (TPMS)” in the Owner’s
Manual for further information. 22. Malfunction Indicator Light (MIL)
The Malfunction Indicator Light (MIL) is part of
an onboard diagnostic (OBDII) system which
monitors the emissions and engine control sys-
tem. If the vehicle is ready for emissions testing, the light
will come on when the ignition is first turned on and
remain on, as a bulb check, until the engine is started. If
the vehicle is not ready for emissions testing the light will
come on when the ignition is first turned on and remain
on for 15 seconds, then blink for 5 seconds, and remain
on until the vehicle is started. If the bulb does not come
on during starting, have the condition investigated
promptly.
If this light comes on and remains on while driving, it
suggests a potential engine control problem and the need
for system service.
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UNDERSTANDING YOUR INSTRUMENT PANEL 23

DIESEL EXHAUST FLUID — CHASSIS CAB ONLY
Your vehicle is equipped with a Selective Catalytic Re-
duction system in order to meet the very stringent diesel
emissions standards required by the Environmental Pro-
tection Agency. Selective Catalytic Reduction (SCR) is the
first and only technology in decades to be as good for the
environment as it is good for business and vehicle
performance.
The purpose of the SCR system is to reduce levels of NOx
(oxides of nitrogen emitted from engines) that are harm-
ful to our health and the environment to an almost
near-zero level. Small quantities of Diesel Exhaust Fluid
(DEF) are injected into the exhaust upstream of a catalyst
where, when vaporized, convert smog-forming nitrogen
oxides (NOx) into harmless nitrogen (N2) and water
vapor (H2O), two natural components of the air we
breathe. You can operate with the comfort that your
vehicle is contributing to a cleaner, healthier world
environment for this and generations to come.
System Overview
This vehicle is equipped with a Diesel Exhaust Fluid
(DEF) injection system and a Selective Catalytic Reduc-
tion (SCR) catalyst to meet the emission requirements.
The DEF injection system consists of the following com-
ponents:
•DEF tank
•DEF pump
•DEF injector
•Electronically-heated DEF lines
•DEF control module
•NOx sensors
•Temperature sensors
•SCR catalyst
88 STARTING AND OPERATING

NOTE:The air filter housing contains a Mass Air Flow
sensor. This sensor is critical to proper engine operation
and component longevity. Any damage or modification
to this sensor could result in major engine and/or
exhaust aftertreatment damage. This includes the use of
non-approved air filters. Use only MOPAR approved air
filters or equivalent.
A visual inspection of the air cleaner filter element is
never recommended under normal circumstances. A
badly restricted element may appear clean while a soiled
element may be quite effective in filtering particles
without restricting air flow. Rely on the Engine Control
Module to determine when a filter change is necessary.
CAUTION!
Many aftermarket performance air filter elements do
not adequately filter the air entering the engine. Use
of such filters can severely damage your engine.
Draining Fuel/Water Separator Filter
The fuel filter and water separator assembly is located on
the driver’s side of the engine. The best access to the
water drain valve is from under the hood.
CAUTION!
•Do not drain the fuel/water separator filter when
the engine is running.
•Diesel fuel will damage blacktop paving surfaces.
Drain the filter into an appropriate container.
If water is detected in the water separator while the
engine is running, or while the ignition switch is in the
ON position, the “Water In Fuel Indicator Light” will
illuminate and an audible chime will be heard five times.
At this point you should stop the engine and drain the
water from the separator.
106 MAINTAINING YOUR VEHICLE

CAUTION!
If the “Water In Fuel Indicator Light” remains on, DO
NOT START the engine before you drain water from
the fuel filter to avoid engine damage.
If the “Water In Fuel Indicator Light” comes on and a
single chime is heard while you are driving, or with the
ignition switch in the ON position, there may be a
problem with your water separator wiring or sensor. See
your authorized dealer for service.
Upon proper draining of the water from the fuel filter, the
“Water In Fuel Indicator Light” will remain illuminated
for approximately 10 seconds. If the water was drained
while the engine was running, the “Water In Fuel Indi-
cator Light” may remain on for approximately three
minutes. NOTE:
Care should be taken in disposing of used fluids
from your vehicle. Used fluids, indiscriminately dis-
carded, can present a problem to the environment. Con-
tact an authorized dealer, service station, or government
agency for advice on recycling programs and for where
used fluids and filters can be properly disposed of in
your area.
Drain the fuel/water separator filter when the “Water In
Fuel Indicator Light” is ON. Within 10 minutes of vehicle
shutdown, turn the drain valve (located on the side of the
filter) counterclockwise 1/4 turn, turn the ignition switch
to the ON position, and allow any accumulated water to
drain. Leave the drain valve open until all water and
contaminants have been removed. When clean fuel is
visible, close the drain valve by turning it clockwise, and
turn the ignition switch to OFF.
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MAINTAINING YOUR VEHICLE 107