2020 Ram 3500 catalytic converter

134GETTING TO KNOW YOUR INSTRUMENT PANEL
automatic transmission control systems. This
warning light will illuminate when the ignition is
in the ON/RUN position before engine start. If
the bulb does not come on when turning the
ignition switch from OFF to ON/RUN, have the
condition checked promptly.
Certain conditions, such as a loose or missing
gas cap, poor quality fuel, etc., may illuminate
the light after engine start. The vehicle should
be serviced if the light stays on through several
typical driving styles. In most situations, the
vehicle will drive normally and will not require
towing.
When the engine is running, the MIL may flash
to alert serious conditions that could lead to
immediate loss of power or severe catalytic
converter damage. The vehicle should be
serviced by an authorized dealer as soon as
possible if this occurs.Electronic Stability Control (ESC) Active
Warning Light — If Equipped
This warning light will indicate when
the Electronic Stability Control system
is Active. The “ESC Indicator Light” in
the instrument cluster will come on
when the ignition is placed in the ON/RUN or
ACC/ON/RUN position, and when ESC is
activated. It should go out with the engine
running. If the “ESC Indicator Light” comes on
continuously with the engine running, a
malfunction has been detected in the ESC
system. If this warning light remains on after
several ignition cycles, and the vehicle has been
driven several miles (kilometers) at speeds
greater than 30 mph (48 km/h), see an
authorized dealer as soon as possible to have
the problem diagnosed and corrected.
The “ESC OFF Indicator Light” and the “ESC
Indicator Light” come on momentarily each
time the ignition is placed in the ON/RUN or
ACC/ON/RUN position.
WARNING!
A malfunctioning catalytic converter, as
referenced above, can reach higher
temperatures than in normal operating
conditions. This can cause a fire if you drive
slowly or park over flammable substances
such as dry plants, wood, cardboard, etc. This
could result in death or serious injury to the
driver, occupants or others.
CAUTION!
Prolonged driving with the Malfunction
Indicator Light (MIL) on could cause damage
to the vehicle control system. It also could
affect fuel economy and driveability. If the
MIL is flashing, severe catalytic converter
damage and power loss will soon occur.
Immediate service is required.

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142GETTING TO KNOW YOUR INSTRUMENT PANEL
BLUE INDICATOR LIGHTS
High Beam Indicator Light
This indicator light will illuminate to
indicate that the high beam
headlights are on. With the low beams
activated, push the multifunction
lever forward (toward the front of the vehicle) to
turn on the high beams. Pull the multifunction
lever rearward (toward the rear of the vehicle) to
turn off the high beams. If the high beams are
off, pull the lever toward you for a temporary
high beam on, "flash to pass" scenario.
ONBOARD DIAGNOSTIC SYSTEM — OBD II
Your vehicle is equipped with a sophisticated
Onboard Diagnostic system called OBD II. This
system monitors the performance of the
emissions, engine, and transmission control
systems. When these systems are operating
properly, your vehicle will provide excellent
performance and fuel economy, as well as
engine emissions well within current
government regulations.
If any of these systems require service, the OBD
II system will turn on the Malfunction Indicator
Light (MIL). It will also store diagnostic codes and other information to assist your service
technician in making repairs. Although your
vehicle will usually be drivable and not need
towing, see an authorized dealer for service as
soon as possible.
ONBOARD DIAGNOSTIC SYSTEM
(OBD II) C
YBERSECURITY
Your vehicle is required to have an Onboard
Diagnostic system (OBD II) and a connection
port to allow access to information related to
the performance of your emissions controls. Authorized service technicians may need to
access this information to assist with the
diagnosis and service of your vehicle and
emissions system.
For further information, refer to “Cybersecurity”
in “Multimedia”.
CAUTION!
Prolonged driving with the MIL on could
cause further damage to the emission
control system. It could also affect fuel
economy and driveability. The vehicle must
be serviced before any emissions tests can
be performed.
If the MIL is flashing while the vehicle is
running, severe catalytic converter damage
and power loss will soon occur. Immediate
service is required.
WARNING!
ONLY an authorized service technician
should connect equipment to the OBD II
connection port in order to read the VIN,
diagnose, or service your vehicle.
If unauthorized equipment is connected to
the OBD II connection port, such as a
driver-behavior tracking device, it may:
Be possible that vehicle systems,
including safety related systems, could
be impaired or a loss of vehicle control
could occur that may result in an acci
-
dent involving serious injury or death.
Access, or allow others to access, infor -
mation stored in your vehicle systems,
including personal information.

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SERVICING AND MAINTENANCE417
Under normal operating conditions, the
catalytic converter will not require
maintenance. However, it is important to keep
the engine properly tuned to ensure proper
catalyst operation and prevent possible catalyst
damage. NOTE:
Intentional tampering with emissions control
systems can result in civil penalties being
assessed against you.
In unusual situations involving grossly
malfunctioning engine operation, a scorching
odor may suggest severe and abnormal catalyst
overheating. If this occurs, stop the vehicle, turn
off the engine and allow it to cool. Service,
including a tune-up to manufacturer's
specifications, should be obtained immediately.
To minimize the possibility of catalytic converter
damage:
Do not interrupt the ignition when the trans
-
mission is in gear and the vehicle is in
motion.
Do not try to start the vehicle by pushing or
towing the vehicle.
Do not idle the engine with any ignition
components disconnected or removed, such
as when diagnostic testing, or for prolonged
periods during very rough idle or malfunc -
tioning operating conditions.
COOLING SYSTEM CAUTION!
The catalytic converter requires the use of
unleaded fuel only. Leaded gasoline will
destroy the effectiveness of the catalyst as
an emissions control device and may seri -
ously reduce engine performance and
cause serious damage to the engine.
Damage to the catalytic converter can
result if your vehicle is not kept in proper
operating condition. In the event of engine
malfunction, particularly involving engine
misfire or other apparent loss of perfor -
mance, have your vehicle serviced
promptly. Continued operation of your
vehicle with a severe malfunction could
cause the converter to overheat, resulting
in possible damage to the converter and
vehicle.
WARNING!
You or others can be badly burned by hot
engine coolant (antifreeze) or steam from
your radiator. If you see or hear steam
coming from under the hood, do not open
the hood until the radiator has had time to
cool. Never open a cooling system pressure
cap when the radiator or coolant bottle is
hot.
Keep hands, tools, clothing, and jewelry
away from the radiator cooling fan when
the hood is raised. The fan starts automati -
cally and may start at any time, whether the
engine is running or not.
When working near the radiator cooling fan,
disconnect the fan motor lead or turn the
ignition to the OFF mode. The fan is
temperature controlled and can start at any
time the ignition is in the ON mode.7

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TECHNICAL SPECIFICATIONS455
Problems that result from using gasoline
containing more than 15% ethanol (E-15) or
gasoline containing methanol are not the
responsibility of the manufacturer and may void
or not be covered under New Vehicle Limited
Warranty.
DO NOT USE E-85 IN NON-FLEX FUEL
V
EHICLES
Non-Flex Fuel Vehicles (FFV) are compatible
with gasoline containing up to 15% ethanol
(E-15). Use of gasoline with higher ethanol
content may void the New Vehicle Limited
Warranty.
If a Non-FFV vehicle is inadvertently fueled with
E-85 fuel, the engine will have some or all of
these symptoms:
Operate in a lean mode.
OBD II Malfunction Indicator Light on.
Poor engine performance.
Poor cold start and cold drivability.
Increased risk for fuel system component
corrosion.
CNG AND LP FUEL SYSTEM
M
ODIFICATIONS
Modifications that allow the engine to run on
Compressed Natural Gas (CNG) or Liquid
Propane (LP) may result in damage to the
engine, emissions, and fuel system
components. Problems that result from running
CNG or LP are not the responsibility of the
manufacturer and may void or not be covered
under the New Vehicle Limited Warranty.
MMT IN GASOLINE
Methylcyclopentadienyl Manganese Tricarbonyl
(MMT) is a manganese-containing metallic
additive that is blended into some gasoline to
increase octane. Gasoline blended with MMT
provides no performance advantage beyond
gasoline of the same octane number without
MMT. Gasoline blended with MMT reduces
spark plug life and reduces emissions system
performance in some vehicles. The
manufacturer recommends that gasoline
without MMT be used in your vehicle. The MMT
content of gasoline may not be indicated on the
gasoline pump; therefore, you should ask your
gasoline retailer whether the gasoline contains
MMT. MMT is prohibited in Federal and
California reformulated gasoline.
FUEL SYSTEM CAUTIONS
CAUTION!
Follow these guidelines to maintain your
vehicle’s performance:
The use of leaded gasoline is prohibited by
Federal law. Using leaded gasoline can
impair engine performance and damage
the emissions control system.
An out-of-tune engine or certain fuel or igni -
tion malfunctions can cause the catalytic
converter to overheat. If you notice a
pungent burning odor or some light smoke,
your engine may be out of tune or malfunc -
tioning and may require immediate service.
Contact an authorized dealer for service
assistance.
The use of fuel additives, which are now
being sold as octane enhancers, is not
recommended. Most of these products
contain high concentrations of methanol.
Fuel system damage or vehicle perfor -
mance problems resulting from the use of
such fuels or additives is not the responsi -
bility of the manufacturer and may void or
not be covered under the New Vehicle
Limited Warranty.8

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