check engine light Ram 2500 2020 User Guide

182SAFETY
The ORC contains a backup power supply
system that may deploy the air bag system even
if the battery loses power or it becomes discon -
nected prior to deployment.
The ORC turns on the Air Bag Warning Light in
the instrument panel for approximately four to
eight seconds for a self-check when the ignition
switch is first in the ON/RUN position. After the
self-check, the Air Bag Warning Light will turn
off. If the ORC detects a malfunction in any part
of the system, it turns on the Air Bag Warning
Light, either momentarily or continuously. A
single chime will sound to alert you if the light
comes on again after initial startup.
The ORC also includes diagnostics that will illu-
minate the instrument panel Air Bag Warning
Light if a malfunction is detected that could
affect the air bag system. The diagnostics also
record the nature of the malfunction. While the
air bag system is designed to be maintenance
free, if any of the following occurs, have an
authorized dealer service the air bag system
immediately.
The Air Bag Warning Light does not come on
during the four to eight seconds when the
ignition switch is first in the ON/RUN position.
The Air Bag Warning Light remains on after
the four to eight-second interval.
The Air Bag Warning Light comes on intermit -
tently or remains on while driving.
NOTE:
If the speedometer, tachometer, or any engine
related gauges are not working, the Occupant
Restraint Controller (ORC) may also be
disabled. In this condition the air bags may not
be ready to inflate for your protection. Have an
authorized dealer service the air bag system
immediately.
Redundant Air Bag Warning Light
If a fault with the Air Bag Warning
Light is detected, which could affect
the Supplemental Restraint System
(SRS), the Redundant Air Bag Warning
Light will illuminate on the instrument panel.
The Redundant Air Bag Warning Light will stay
on until the fault is cleared. In addition, a single
chime will sound to alert you that the Redun -
dant Air Bag Warning Light has come on and a
fault has been detected. If the Redundant Air
Bag Warning Light comes on intermittently or
remains on while driving have an authorized
dealer service the vehicle immediately.
For additional information regarding the Redun -
dant Air Bag Warning Light refer to “Getting To
Know Your Instrument Panel” section of this
manual.
Front Air Bags
This vehicle has front air bags and lap/shoulder
belts for both the driver and front passenger.
The front air bags are a supplement to the seat
belt restraint systems. The driver front air bag is
mounted in the center of the steering wheel.
The passenger front air bag is mounted in the
WARNING!
Ignoring the Air Bag Warning Light in your
instrument panel could mean you won’t have
the air bag system to protect you in a
collision. If the light does not come on as a
bulb check when the ignition is first turned
on, stays on after you start the vehicle, or if it
comes on as you drive, have an authorized
dealer service the air bag system
immediately.

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SAFETY189
(Continued)
Enhanced Accident Response System
In the event of an impact, if the communication
network remains intact, and the power remains
intact, depending on the nature of the event,
the Occupant Restraint Controller (ORC) will
determine whether to have the Enhanced Acci -
dent Response System perform the following
functions:
Cut off fuel to the engine (if equipped)
Cut off battery power to the electric motor (if
equipped)
Flash hazard lights as long as the battery has
power
Turn on the interior lights, which remain on
as long as the battery has power or for
15 minutes from the intervention of the
Enhanced Accident Response System
Unlock the power door locks
Your vehicle may also be designed to perform
any of these other functions in response to the
Enhanced Accident Response System:
Turn off the Fuel Filter Heater, Turn off the
HVAC Blower Motor, Close the HVAC Circula -
tion Door
Cut off battery power to the:
Engine
Electric Motor (if equipped)
Electric power steering
Brake booster
Electric park brake
Automatic transmission gear selector
Horn
Front wiper
Headlamp washer pump
NOTE:
After an accident, remember to cycle the ignition
to the STOP (OFF/LOCK) position and remove the
key from the ignition switch to avoid draining the
battery. Carefully check the vehicle for fuel leaks
in the engine compartment and on the ground
near the engine compartment and fuel tank
before resetting the system and starting the
engine. If there are no fuel leaks or damage to the
vehicle electrical devices (e.g. headlights) after an
accident, reset the system by following the proce -
dure described below. If you have any doubt,
contact an authorized dealer.
Enhanced Accident Response System Reset
Procedure
In order to reset the Enhanced Accident
Response System functions after an event, the
ignition switch must be changed from ignition
START or ON/RUN to ignition OFF. Carefully
check the vehicle for fuel leaks in the engine
compartment and on the ground near the
engine compartment and fuel tank before reset -
ting the system and starting the engine.
Maintaining Your Air Bag System
WARNING!
Modifications to any part of the air bag
system could cause it to fail when you need
it. You could be injured if the air bag system
is not there to protect you. Do not modify
the components or wiring, including adding
any kind of badges or stickers to the
steering wheel hub trim cover or the upper
passenger side of the instrument panel. Do
not modify the front bumper, vehicle body
structure, or add aftermarket side steps or
running boards.
4

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210SAFETY
(Continued)
Periodic Safety Checks You Should Make
Outside The Vehicle
Tires
Examine tires for excessive tread wear and
uneven wear patterns. Check for stones, nails,
glass, or other objects lodged in the tread or
sidewall. Inspect the tread for cuts and cracks.
Inspect sidewalls for cuts, cracks, and bulges.
Check the wheel bolts for tightness. Check the
tires (including spare) for proper cold inflation
pressure.
Lights
Have someone observe the operation of brake
lights and exterior lights while you work the
controls. Check turn signal and high beam indi -
cator lights on the instrument panel.
Door Latches
Check for proper closing, latching, and locking.
Fluid Leaks
Check area under the vehicle after overnight
parking for fuel, coolant, oil, or other fluid leaks.
Also, if gasoline fumes are detected or if fuel, or
brake fluid leaks are suspected, the cause
should be located and corrected immediately.
ONLY install floor mats designed to fit your
vehicle. NEVER install a floor mat that
cannot be properly attached and secured to
your vehicle. If a floor mat needs to be
replaced, only use a FCA approved floor
mat for the specific make, model, and year
of your vehicle.
ONLY use the driver’s side floor mat on the
driver’s side floor area. To check for inter -
ference, with the vehicle properly parked
with the engine off, fully depress the accel-
erator, the brake, and the clutch pedal (if
present) to check for interference. If your
floor mat interferes with the operation of
any pedal, or is not secure to the floor,
remove the floor mat from the vehicle and
place the floor mat in your trunk.
ONLY use the passenger’s side floor mat on
the passenger’s side floor area.
WARNING! (Continued)
ALWAYS make sure objects cannot fall or
slide into the driver’s side floor area when
the vehicle is moving. Objects can become
trapped under accelerator, brake, or clutch
pedals and could cause a loss of vehicle
control.
NEVER place any objects under the floor
mat (e.g., towels, keys, etc.). These objects
could change the position of the floor mat
and may cause interference with the accel -
erator, brake, or clutch pedals.
If the vehicle carpet has been removed and
re-installed, always properly attach carpet
to the floor and check the floor mat
fasteners are secure to the vehicle carpet.
Fully depress each pedal to check for inter -
ference with the accelerator, brake, or
clutch pedals then re-install the floor mats.
It is recommended to only use mild soap
and water to clean your floor mats. After
cleaning, always check your floor mat has
been properly installed and is secured to
your vehicle using the floor mat fasteners
by lightly pulling mat.
WARNING! (Continued)

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218STARTING AND OPERATING
5. After engine start-up, check to see that
there is oil pressure.
6. Release the parking brake and drive.
NOTE:
Engine idle speed will automatically increase
to 1,000 RPM and engage the Variable
Geometry Turbocharger at low coolant
temperatures to improve engine warm-up.
The engine will not automatically crank after
the engine “Wait To Start” telltale goes off if
a door or the hood is ajar.
If the engine stalls, or if the ignition switch is
left ON for more than two minutes after the
“Wait To Start” telltale goes out, reset the
intake air heater by turning the ignition
switch to the OFF position for at least
5 seconds and then back ON. Repeat steps
1 through 7 of “Keyless Enter-N-Go Starting Procedure – Engine Manifold Air Tempera
-
ture Below 66° F (19° C).”
Extreme Cold Weather
The Cummins® Turbo Diesel engine is
equipped with several features designed to
assist cold weather starting and operation:
The engine block heater is a resistance
heater installed in the water jacket of the
engine just above and behind the oil filter. It
requires a 110–115 Volt AC electrical outlet
with a grounded, three-wire extension cord.
NOTE:
The engine block heater cord is a factory
installed option. If your vehicle is not equipped,
heater cords are available from an authorized
Mopar dealer.
A 12 Volt heater built into the fuel filter hous -
ings aid in preventing fuel gelling. It is
controlled by a built-in thermostat.
A intake air heater system both improves
engine starting and reduces the amount of
white smoke generated by a warming engine.
Normal Starting Procedure — Engine
Manifold Air Temperature Above 66° F
(19° C)
Observe the instrument panel cluster lights
when starting the engine.

1. Always apply the parking brake.

2. Shift into PARK for an automatic transmis -
sion.
3. Place the ignition switch in the ON position and watch the instrument panel cluster
lights.
4. Place the ignition switch in the START posi -
tion and crank the engine. Do not press the
accelerator during starting.
CAUTION!
Do not crank engine for more than 25 seconds
at a time or starter motor damage may result.
Turn the ignition switch to the OFF position and
wait at least two minutes for the starter to cool
before repeating start procedure.
CAUTION!
If the “Water in Fuel Indicator Light” remains
on, DO NOT START the engine before you
drain the water from the fuel filters to avoid
engine damage. Refer to “Draining Fuel/
Water Separator Filter” in “Servicing And
Maintenance” for further information.

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STARTING AND OPERATING219
5. Check that the oil pressure warning light
has turned off.
6. Release the parking brake.
Starting Procedure — Engine Manifold Air
Temperature 0°F To 66°F (–18°C to 19°C)
NOTE:
The temperature displayed in the instrument
cluster does not necessarily reflect the engine
manifold air temperature. Refer to “Instrument
Cluster Display” in “Getting To Know Your
Instrument Panel” for further information.
When engine temperatures fall below 66°F
(19°C) the “Wait To Start Light” will remain on
indicating the intake air heater system is active.
Follow the steps in the “Normal Starting” proce -
dure except:
1. The “Wait To Start” telltale will remain on
for a period of time that varies depending
on the engine temperature.

2. While the “Wait To Start” telltale is on, the instrument cluster will additionally display a
gauge or bar whose initial length represents
the full “Wait To Start” time period. Its
length will decrease until it disappears
when the “Wait To Start” time has elapsed.
3. After the “Wait To Start” telltale goes off, place the ignition switch in the START posi -
tion. Do not press the accelerator during
starting. 4. After engine start-up, check that the oil
pressure warning light has turned off.
5. Release the parking brake and drive.
NOTE:
Engine idle speed will automatically increase
to 1,000 RPM and engage the Variable
Geometry Turbocharger at low coolant
temperatures to improve engine warm-up.
Automatic equipped vehicles with optional
Keyless Enter-N-Go – If the start button is
pushed once while in park with the ignition
off and driver’s foot on the brake pedal, the
vehicle will automatically crank and start
after the Wait to Start time has elapsed. If it
is desired to abort the start process before it
CAUTION!
Do not crank engine for more than 25 seconds
at a time or starter motor damage may result.
Turn the ignition switch to the OFF position and
wait at least two minutes for the starter to cool
before repeating start procedure.
CAUTION!
If the “Water in Fuel Indicator Light” remains
on, DO NOT START the engine before you
drain the water from the fuel filters to avoid
engine damage. Refer to “Draining Fuel/
Water Separator Filter” in “Servicing And
Maintenance” for further information.
CAUTION!
Do not crank engine for more than 25 seconds
at a time or starter motor damage may result.
Turn the ignition switch to the OFF position and
wait at least two minutes for the starter to cool
before repeating start procedure.
5

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STARTING AND OPERATING225

1. With the transmission in PARK, the parking
brake applied, and the engine running,
push the speed control switch to the ON
position, then push the SET switch.

2. The engine RPM will go up to 1,100 RPM. To increase the RPM, push and hold the
ACCEL/RESUME switch and the idle speed
will increase to approximately 1,500 RPM.
To decrease the RPM, push and hold the
DECEL switch and the idle speed will
decrease to approximately 1,100 RPM.
3. To cancel the Idle–Up feature, either push the CANCEL switch, push the ON/OFF
switch, or press the brake pedal.
Noise
Diesel engines can create noises that may
seem concerning. The nature of a diesel engine
is compression ignition where compressed air and fuel are mixed and ignited. Weather, baro
-
metric pressure, altitude, and temperature will
affect how fuel is ignited in the engine. Engines
will sound different from day to day or previous
model years. Clicking, ticking, or light knocking
is normal and will change from day to day, as
the engine breaks in, and can vary with changes
in ambient temperature. Clicking sound from
under the hood shortly after vehicle shutdown is
normal as actuators such as the EGR valve are
cycled. Fuel pump noise may increase during
low speed/light load conditions when ambient
temperature is above 100°F (38°C), and when
fuel tank level is below 10% which is a normal
condition of the fuel system and controls
strategy. Diesel equipped vehicles also have an
exhaust after-treatment system to reduce emis -
sions utilizing a DPF (refer to “Odor” in this
section for further information) and a Selective
Reduction Catalyst (SCR). The SCR reduces
Nitrogen Oxides (NOx) using the Diesel Exhaust Fluid (DEF) system. DEF is injected directly into
the SCR through a dosing module. This process
will create a clicking sound and at times, will
make noise even with the vehicle shut off. This
is normal as the DEF dosing module is purging
DEF. If at any time the check engine light is on,
please visit an authorized dealer.
Stopping The Engine
Idle the engine a few minutes before routine
shutdown. After full load operation, idle the
engine three to five minutes before shutting it
down. This idle period will allow the lubricating
oil and coolant to carry excess heat away from
the combustion chamber, bearings, internal
components, and turbocharger. This is espe
-
cially important for turbocharged, charge
air-cooled engines. Refer to the following chart
for proper engine shutdown:
Driving Condition Load Turbocharger Temperature Idle Time (min.) Before Engine
Shutdown
Stop and Go EmptyCoolLess than One
Stop and Go Medium -One
Highway Speeds MediumWarmTwo
5

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260STARTING AND OPERATING
Driving Through Water
Extreme care should be taken crossing any type
of water. Water crossings should be avoided if
possible and only be attempted when neces -
sary, in a safe responsible manner. You should
only drive through areas which are designated
and approved. You should tread lightly and
avoid damage to the environment. You should
know your vehicle's abilities and be able to
recover it if something goes wrong. You should
never stop or shut a vehicle off when crossing
deep water unless you ingested water into the
engine air intake. If the engine stalls do not
attempt to restart it. Determine if it has ingested
water first. The key to any crossing is low and
slow. You want to use FIRST gear in 4WD LOW
and proceed very slowly with a constant slow
speed (3-5 mph [5–8 km/h] maximum) and
light throttle. Keep the vehicle moving; do not
try to accelerate through the crossing. After
crossing any water higher than the bottom of
the axle differentials, you should inspect all of
the vehicle fluids for signs of water ingestion.
Before You Cross Any Type Of Water – As you
approach any type of water you need to
determine if you can cross it safely and
responsibly. If necessary, get out and walk
through the water or probe it with a stick. You
need to be sure of its depth, approach angle,
current and bottom condition. Be careful of
murky or muddy waters, check for hidden
obstacles. Make sure you will not be
intruding on any wildlife and you can recover
the vehicle if necessary. The key to a safe
crossing is the water depth, current and
bottom conditions. On soft bottoms the
vehicle will sink in, effectively increasing the
water level on the vehicle. Be sure to
consider this when determining the depth
and the ability to safely cross.
Crossing Puddles, Pools, Flooded Areas Or
Other Standing Water – Puddles, pools,
flooded or other standing water areas
normally contain murky or muddy waters.
These water types normally contain hidden
obstacles and make it difficult to determine
an accurate water depth, approach angle,
and bottom condition. Murky or muddy water
holes are where you want to hook up tow
straps prior to entering. This makes for a
faster, cleaner and easier vehicle recovery. If
you are able to determine you can safely
cross, than proceed using the low and slow
method.
Crossing Ditches, Streams, Shallow Rivers Or
Other Flowing Water – Flowing water can be
extremely dangerous. Never attempt to cross
a fast running stream or river even in shallow
water. Fast moving water can easily push
your vehicle downstream sweeping it out of
control. Even in very shallow water, a high
current can still wash the dirt out from
CAUTION!
Water ingestion into the axles, transmission,
transfer case, engine or vehicle interior can
occur if you drive too fast or through too deep
of water. Water can cause permanent
damage to engine, driveline or other vehicle
components and your brakes will be less
effective once wet and/or muddy.
CAUTION!
Muddy waters can reduce the cooling system
effectiveness by depositing debris onto the
radiator.

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264STARTING AND OPERATING
Check threaded fasteners for looseness,
particularly on the chassis, drivetrain compo -
nents, steering, and suspension. Retighten
them, if required, and torque to the values
specified in the Service Manual.
Check for accumulations of plants or brush.
These things could be a fire hazard. They
might hide damage to fuel lines, brake hoses,
axle pinion seals, and propeller shafts.
After extended operation in mud, sand,
water, or similar dirty conditions, have the
radiator, fan, brake rotors, wheels, brake
linings, and axle yokes inspected and
cleaned as soon as possible.
If you experience unusual vibration after
driving in mud, slush or similar conditions,
check the wheels for impacted material.
Impacted material can cause a wheel imbal-
ance and freeing the wheels of it will correct
the situation.
LIMITED-SLIP DIFFERENTIAL
The limited-slip differential provides additional
traction on snow, ice, mud, sand and gravel,
particularly when there is a difference between
the traction characteristics of the surface under
the right and left rear wheels. During normal
driving and cornering, the limited-slip unit
performs similarly to a conventional differential.
On slippery surfaces, however, the differential
delivers more of the driving effort to the rear
wheel having the better traction.
The limited-slip differential is especially helpful
during slippery driving conditions. With both
rear wheels on a slippery surface, a slight appli -
cation of the accelerator will supply maximum
traction. When starting with only one rear wheel
on an excessively slippery surface, slight
momentary application of the parking brake
may be necessary to gain maximum traction. Care should be taken to avoid sudden accelera-
tions when both rear wheels are on a slippery
surface. This could cause both rear wheels to
spin, and allow the vehicle to slide sideways on
the crowned surface of a road or in a turn.
WINCH USAGE — POWER WAGON ONLY (IF
EQUIPPED)
Things To Know Before Using Your Winch
General Winch Information
Your vehicle is equipped with an electric vehicle
recovery winch. This winch uses the electrical
power from the vehicle charging system to
power a motor that winds the winch rope onto
the winch drum via planetary gear reduction. By
nature, a winch is capable of generating very
high forces and should be used with care. Do
WARNING!
Abrasive material in any part of the brakes
may cause excessive wear or unpredictable
braking. You might not have full braking
power when you need it to prevent a collision.
If you have been operating your vehicle in
dirty conditions, get your brakes checked and
cleaned as necessary.
WARNING!
On vehicles equipped with a limited-slip
differential never run the engine with one rear
wheel off the ground since the vehicle may
drive through the rear wheel remaining on the
ground. You could lose control of the vehicle.

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STARTING AND OPERATING329
Speed Control — If Equipped
Do not use on hilly terrain or with heavy
loads.
When using the Speed Control, if you experi -
ence speed drops greater than 10 mph
(16 km/h), disengage until you can get back
to cruising speed.
Use Speed Control in flat terrain and with
light loads to maximize fuel efficiency.
Cooling System
To reduce potential for engine and transmission
overheating, take the following actions:
City Driving
In city traffic — while stopped, place the trans -
mission in NEUTRAL, but do not increase
engine idle speed.
Highway Driving
Reduce speed.
Temporarily turn off air conditioning.
Air Suspension System
To aid in attaching/detaching the trailer from
the vehicle, the air suspension system can be
used. Refer to “Air Suspension System” in “Starting And Operating” for further informa
-
tion.
NOTE:
The vehicle must remain in the engine running
position while attaching a trailer for proper
leveling of the air suspension system.
SNOWPLOW
Snowplow Prep Packages are available as a
factory installed option. These packages
include components necessary to equip your
vehicle with a snowplow.
NOTE:
Before installation of a snowplow it is highly
recommended that the owner/installer obtain
and follow the recommendations contained
within the current Body Builders Guide. See
your authorized dealer, installer or snowplow
manufacturer for this information. There are
unique electrical systems that must be
connected to properly ensure operator safety
and prevent overloading vehicle systems.
Before Plowing
Check the hydraulic system for leaks and
proper fluid level.
Check the mounting bolts and nuts for proper
tightness.
Check the runners and cutting edge for
excessive wear. The cutting edge should be
¼ to ½ inches (6 cm to 1.2 cm) above ground
in snow plowing position.
Check that snowplow lighting is connected
and functioning properly.
WARNING!
Attaching a snowplow to this vehicle could
adversely affect performance of the airbag
system in a collision. Do not expect that the
airbag will perform as described earlier in this
manual.
CAUTION!
The “Lamp Out” indicator could illuminate if
exterior lamps are not properly installed.
5

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336STARTING AND OPERATING
(Continued)
Off-Road Driving Tips
Care should be taken when attempting to climb
steep hills or driving diagonally across a hill or
slope. If natural obstacles force you to travel
diagonally up or down a hill, choose a mild angle
and keep as little side tilt as possible. Keep the
vehicle moving and make turns slowly and
cautiously. If you must back down a hill, back straight down
using REVERSE gear. Never back down in
NEUTRAL or diagonally across the hill.
When driving over sand, mud, and other soft
terrain, shift to low gear and drive steadily.
Apply the accelerator slowly to avoid spinning
the wheels.
Do not reduce the tire pressures for this type of
driving.
After Driving Off-Road
Off-road operation puts more stress on your
vehicle than does most on-road driving. After
going off-road, it is always a good idea to check
for damage. That way you can get any problems
taken care of right away and have your vehicle
ready when you need it.
Completely inspect the underbody of your
vehicle. Check tires, body structure, steering,
suspension, and exhaust system for damage.
Inspect the radiator for mud and debris and
clean as required.
Driving through standing water limits your
vehicle’s braking capabilities, which
increases stopping distances. Therefore,
after driving through standing water, drive
slowly and lightly press on the brake pedal
several times to dry the brakes.
Failure to follow these warnings may result
in injuries that are serious or fatal to you,
your passengers, and others around you.
CAUTION!
Always check the depth of the standing
water before driving through it. Never drive
through standing water that is deeper than
the bottom of the tire rims mounted on the
vehicle.
Determine the condition of the road or the
path that is under water and if there are any
obstacles in the way before driving through
the standing water.
Do not exceed 5 mph (8 km/h) when
driving through standing water. This will
minimize wave effects.
WARNING!
(Continued)
Driving through standing water may cause
damage to your vehicle’s drivetrain compo -
nents. Always inspect your vehicle’s fluids
(i.e., engine oil, transmission, axle, etc.) for
signs of contamination (i.e., fluid that is
milky or foamy in appearance) after driving
through standing water. Do not continue to
operate the vehicle if any fluid appears
contaminated, as this may result in further
damage. Such damage is not covered by
the New Vehicle Limited Warranty.
Getting water inside your vehicle’s engine
can cause it to lock up and stall out, and
cause serious internal damage to the
engine. Such damage is not covered by the
New Vehicle Limited Warranty.
CAUTION! (Continued)

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