Tire Ram 2500 2018 Service Manual

WARNING!(Continued)
injury or damage to the system, see your authorized
dealer for service.
Air Suspension Modes
The Air Suspension system has multiple modes to protect
the system in unique situations:
AERO Mode
To improve aerodynamics, the air suspension system has a
feature which will put the vehicle into AERO height
automatically. Refer to “Instrument Cluster Display” in
“Getting To Know Your Instrument Panel” for further
information.
NOTE:This mode is intended to be enabled with engine
running.
Tire/Jack Mode
To assist with changing a tire, the air suspension system
has a feature which allows the automatic leveling to be
disabled. Refer to “Instrument Cluster Display” in “Get-
ting To Know Your Instrument Panel” or “Uconnect Set-
tings” in “Multimedia” if equipped with a touch screen
radio for further information. NOTE:
This mode is intended to be enabled with engine
running.
Transport Mode
For towing your vehicle with four wheels off the road, the
air suspension system has a feature which will put the
vehicle into Entry/Exit height and disable the automatic
load leveling system. Refer to “Instrument Cluster Dis-
play” in “Getting To Know Your Instrument Panel” or
“Uconnect Settings” in “Multimedia” if equipped with a
touch screen radio for further information.
NOTE: This mode is intended to be enabled with engine
running.
Wheel Alignment Mode
Before performing a wheel alignment, this mode must be
enabled. Refer to “Instrument Cluster Display” in “Getting
To Know Your Instrument Panel” or “Uconnect Settings” in
“Multimedia” if equipped with a touch screen radio for
further information.
NOTE: This mode is intended to be enabled with engine
running.
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STARTING AND OPERATING 353

Pushing the “Up” button once will move the suspension
one position higher from the current position, assuming all
conditions are met (i.e. key in ON/RUN position, engine
running, speed below threshold, etc). The “Up” button can
be pushed multiple times, each push will raise the re-
quested level by one position up to a maximum position of
OR or the highest position allowed based on current
conditions (i.e. vehicle speed, etc).
Pushing the “DOWN” button once will move the suspen-
sion one position lower from the current level, assuming all
conditions are met (i.e. key in ON/RUN position, engine
running, doors closed, speed below threshold, etc). The
“DOWN” button can be pushed multiple times, each push
will lower the requested level by one position down to a
minimum of Entry/Exit Mode or the lowest position
allowed based on current conditions (i.e. vehicle speed,
etc.)
Automatic height changes will occur based on vehicle
speed and the current vehicle height. The indicator lamps
and instrument cluster display messages will operate the
same for automatic changes and user requested changes.
•Off-Road (OR) – Indicator lamps 3, 4, 5 and 6 will be
illuminated when the vehicle is in OR. •
Normal Ride Height (NRH) – Indicator lamps 3, 4 and 5
will be illuminated when the vehicle is in NRH.
• Aero Mode – Indicator lamps 3 and 4 will be illuminated
when the vehicle is in Aero Mode.
• Entry/Exit Mode – Indicator lamp 3 will be illuminated
when the vehicle is in Entry Exit Mode. Entry/Exit
mode can be requested up to 33 mph (53 km/h). If
vehicle speed is reduced to, and kept below, 15 mph
(24 km/h) indicator lamp 3 will flash and indicator lamp
4 will remain solid until Entry/Exit Mode is achieved at
which point indicator lamp 4 will turn off.
• Transport Mode – No indicator lamps will be illumi-
nated. Transport Mode is disabled by driving the ve-
hicle.
• Tire/Jack Mode – Indicator lamps 3 and 6 will be
illuminated. Tire/Jack Mode is disabled by driving the
vehicle.
• Wheel Alignment Mode – Indicator lamps 3, 4 and 5 will
be illuminated. Wheel Alignment Mode is disabled by
driving the vehicle.
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STARTING AND OPERATING 355

AIR SUSPENSION SYSTEM (2500/3500 MODELS) —
IF EQUIPPED
Description
This air suspension system is a rear leveling ride height
system. The main purpose of this system is to maintain the
truck’s rear ride height level. There are two selectable
heights that can be chosen based on your operating condi-
tions.
The system requires that the ignition be in ON/RUN
position or the engine running with zero vehicle speed for
all user requested changes and load leveling.Normal Ride Height (NRH)
– This is the standard position
of the suspension and is meant for normal driving. It will
automatically adjust to maintain the rear ride height as
conditions change.
Alternate Trailer Height (ATH) – Lowers the vehicle
approximately 1 in (25 mm) for a level truck, to be used as
required while trailer towing. It will automatically adjust
to maintain the rear ride height as conditions change.
Trailer Decoupling/Unloading - The air suspension sys-
tem will load level (lower/exhaust only) for up to 10
minutes after the vehicle is turned off. This allows for easy
removal of a trailer and/or load from the back of the truck
by maintaining the ride height. After 10 minutes you will
need to turn the ignition to the run position for the air
suspension to maintain ride height. If the air suspension
system is disabled using the settings menu (Tire Jack Mode,
Transport Mode or Alignment Mode) the system will
remain disabled when the vehicle is turned off. Reactivat-
ing the air suspension can be accomplished via the settings
menu or driving the vehicle above 5 mph (8 km/h) for Tire
Jack Mode or Alignment Mode and 16 mph (26 km/h) for
Transport Mode.
Rear Leveling Ride Height Switch
356 STARTING AND OPERATING

NOTE:
•Most 3500 models will not lower to Alternate Trailer
Height (ATH) when unloaded.
• Refer to “Trailer Towing” in “Starting And Operating”
for further information.
Ignition OFF Behavior
For a predetermined amount of time after the ignition is off
the air suspension may adjust to maintain a proper appear-
ance.
WARNING!
The air suspension system uses a high pressure vol-
ume of air to operate the system. To avoid personal
injury or damage to the system, see your authorized
dealer for service.
Air Suspension Modes
The air suspension system has multiple modes to protect
the system in unique situations:
Tire/Jack Mode
To assist with changing a tire, the air suspension system
has a feature which allows the automatic leveling to be disabled. This mode is intended to be enabled with engine
running. Refer to “Instrument Cluster Display” in “Getting
To Know Your Instrument Panel” or “Uconnect Settings” in
“Multimedia” if equipped with a touch screen radio for
further information.
NOTE:
This mode is intended to be enabled with engine
running.
Transport Mode
For towing your vehicle with four wheels off the road, the
air suspension system has a feature which will put the
vehicle below Normal Ride Height (NRH) and disable the
automatic load leveling system. This mode is intended to
be enabled with engine running. Refer to “Instrument
Cluster Display” in “Getting To Know Your Instrument
Panel” or “Uconnect Settings” in “Understanding Your
Instrument Panel” if equipped with a touch screen radio
for further information.
NOTE: This mode is intended to be enabled with engine
running.
Wheel Alignment Mode
Before performing a wheel alignment this mode must be
enabled. Refer to “Instrument Cluster Display” in “Getting
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STARTING AND OPERATING 357

To Know Your Instrument Panel” or “Uconnect Settings” in
“Multimedia” if equipped with a touch screen radio for
further information.
NOTE:This mode is intended to be enabled with engine
running.
Protection Strategy
In order to “protect” the air suspension system, the vehicle
will disable load leveling as required (suspension over-
loaded, battery charge low, etc.). Load leveling will auto-
matically resume as soon as system operation requirements
are met. See your authorized dealer if system does not
resume.
Instrument Cluster Display Messages
When the appropriate conditions exist, a message will
appear in the instrument cluster display. Refer to “Instru-
ment Cluster Display” in “Getting To Know Your Instru-
ment Panel” for further information.
An audible chime will be heard whenever a system error
has been detected.
See your authorized dealer for system service if normal
operation does not resume.
Operation
Pushing the Alternate Trailer Height (ATH) button once
while at Normal Ride Height (NRH), will lower the vehicle
to Alternate Trailer Height (ATH) and will illuminate the
LED.
NOTE: The LED will continuously blink until vehicle
Alternate Trailer Height (ATH) has been achieved and the
LED will turn off.
Pushing the Alternate Trailer Height (ATH) again will raise
the vehicle to Normal Ride Height (NRH).
NOTE: The LED will continuously blink until Normal Ride
Height (NRH) has been achieved.
• Transport Mode – No indicator lamps will be illumi-
nated. Transport Mode is disabled by driving the ve-
hicle.
• Tire/Jack Mode – No indicator lamps will be illumi-
nated. Tire/Jack Mode is disabled by driving the vehicle.
• Wheel Alignment Mode – No indicator lamps will be
illuminated. Wheel Alignment Mode is disabled by
driving the vehicle.
358 STARTING AND OPERATING

AXLE LOCKER SYSTEM — POWER WAGON
MODELS ONLY (IF EQUIPPED)
This vehicle is equipped with electronically locking front
and rear differentials. These differentials, when engaged,
mechanically lock together the axle shafts forcing the
wheels to spin at an equal rate. This allows the vehicle to
maintain its momentum and prevents it from becoming
stuck. The locking front and rear differentials should only
be engaged during low-speed, extreme off-road situations
where one wheel is likely to not be in contact with the
ground. It is not recommended to drive the vehicle with
the differentials locked on pavement due to the reduced
ability to turn and speed limitations.
CAUTION!
•Do not lock the front or rear axle on hard surfaced
roads. The ability to steer the vehicle is reduced and
damage to the drivetrain may occur when the axles
are locked on hard surfaced roads.
• Do not try to lock the rear axle if the vehicle is stuck
and the tires are spinning. You can damage drivetrain
components. Lock the rear axle before attempting
situations or navigating terrain, which could possi-
bly cause the vehicle to become stuck.
Axle Lock Selector
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STARTING AND OPERATING 359

stop, try turning your steering wheel no more than a ¼
turn quickly back and forth, while still applying throttle.
This will allow the tires to get a freshbiteand help
maintain your momentum.
CAUTION!
On icy or slippery roads, do not downshift at high
engine RPMs or vehicle speeds because engine brak-
ing may cause skidding and loss of control.
• Mud – Deep mud creates a great deal of suction around
the tires and is very difficult to get through. You should
use 4LO (Low Range) with a gear low enough to
maintain your momentum without shifting. If you start
to slow to a stop, try turning your steering wheel no
more than a ¼ turn quickly back and forth for additional
traction. Mud holes pose an increased threat of vehicle
damage and getting stuck. They are normally full of
debris from previous vehicles getting stuck. As a good
practice before entering any mud hole, get out and
determine how deep it is, if there are any hidden
obstacles and if the vehicle can be safely recovered if
stuck. •
Sand – Soft sand is very difficult to travel through with
full tire pressure. When crossing soft sandy spots in a
trail maintain your vehicle’s momentum and do not
stop. The key to driving in soft sand using the appro-
priate tire pressure, accelerating slowly, avoiding abrupt
maneuvers and maintaining the vehicle’s momentum. If
you are going to be driving on large soft sandy areas or
dunes, reduce your tire pressure to a minimum of 15 psi
(103 kPa) to allow for a greater tire surface area. Reduced
tire pressure will drastically improve your traction and
handling, while driving on the soft sand, but you must
return the tires to normal air pressure before driving on
pavement or other hard surfaces. Be sure you have a
way to air the tires back up prior to reducing the
pressure.
CAUTION!
Reduced tire pressures may cause tire unseating and
total loss of air pressure. To reduce the risk of tire
unseating, while at a reduced tire pressure, reduce your
speed and avoid sharp turns or abrupt maneuvers.
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Crossing Obstacles (Rocks And Other High Points)
While driving off road, you will encounter many types of
terrain. These varying types of terrain bring different types
of obstacles. Before proceeding review the path ahead to
determine the correct approach and your ability to safely
recover the vehicle if something goes wrong. Keeping a
firm grip on the steering wheel, bring the vehicle to a
complete stop and then inch the vehicle forward until it
makes contact with the object. Apply the throttle lightly
while holding a light brake pressure and ease the vehicle
up and over the object.
WARNING!
Crossing obstacles can cause abrupt steering system
loading which could cause you to loose control of your
vehicle.
Using A Spotter
There are many times where it is hard to see the obstacle or
determine the correct path. Determining the correct path
can be extremely difficult when you are confronting many
obstacles. In these cases have someone guide you over,
through, or around the obstacle. Have the person stand asafe distance in front of you where they can see the
obstacle, watch your tires and undercarriage, and guide
you through.
Crossing Large Rocks
When approaching large rocks, choose a path which en-
sures you drive over the largest with your tires. This will
lift your undercarriage over the obstacle. The tread of the
tire is tougher and thicker than the side wall and is
designed to take the abuse. Always look ahead and make
every effort to cross the large rocks with your tires.
CAUTION!
•
Never attempt to straddle a rock that is large enough
to strike your axles or undercarriage.
• Never attempt to drive over a rock which is large
enough to contact the door sills.
Crossing A Ravine, Gully, Ditch, Washout Or Rut
When crossing a ravine, gully, ditch, washout or a large rut,
the angled approach is the key to maintaining your vehi-
cle’s mobility. Approach these obstacles at a 45-degree
angle and let each tire go through the obstacle indepen-
dently. You need to use caution when crossing large
obstacles with steep sides. Do not attempt to cross any
366 STARTING AND OPERATING

large obstacle with steep sides at an angle great enough to
put the vehicle at risk of a rollover. If you get caught in a
rut, dig a small trench to the right or left at a 45-degree
angle ahead of the front tires. Use the removed dirt to fill
the rut ahead of the turnout you just created. You should
now be able to drive out following the trench you just
created at a 45-degree angle.
WARNING!
There is an increased risk of rollover when crossing an
obstacle, at any angle, with steep sides.
Crossing Logs
To cross a log, approach it at a slight angle (approximately
10 to 15 degrees). This allows one front tire to be on top of
the log while the other just starts to climb the log. While
climbing the log, modulate your brake and accelerator to
avoid spinning the log out from under your tires. Then
ease the vehicle off the log using your brakes.
CAUTION!
Do not attempt to cross a log with a greater diameter
than the running ground clearance or the vehicle will
become high centered.
Getting High Centered
If you get hung up or high centered on an object, get out of
the vehicle and try to determine what the vehicle is hung
up on, where it is contacting the underbody and what is the
best direction to recover the vehicle. Depending on what
you are in contact with, jack the vehicle up and place a few
rocks under the tires so the weight is off of the high point
when you let the vehicle down. You can also try rocking the
vehicle or winching the vehicle off the object.
CAUTION!
Winching or rocking the vehicle off hard objects in-
creases the risk of underbody damage.
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STARTING AND OPERATING 367

Hill Climbing
Hill climbing requires good judgment and a good under-
standing of your abilities and your vehicle’s limitations.
Hills can cause serious problems. Some are just too steep to
climb and should not be attempted. You should always feel
confident with the vehicle and your abilities. You should
always climb hills straight up and down. Never attempt to
climb a hill on an angle.
•Before Climbing A Steep Hill – As you approach a hill
consider its grade or steepness. Determine if it is too
steep. Look to see what the traction is on the hill side
trail. Is the trail straight up and down? What is on top
and the other side? Are there ruts, rocks, branches or
other obstacles on the path? Can you safely recover the
vehicle if something goes wrong? If everything looks
good and you feel confident, then change transmission
into a lower gear, shift the transfer case into 4LO (Low)
and proceed with caution. You should use first gear and
4LO (Low Range) for very steep hills.
• Driving Up Hill – Once you have determined your
ability to proceed and have shifted into the appropriate
gear, line your vehicle up for the straightest possible run.
Accelerate with an easy constant throttle and apply
more power as you start up the hill. Do not race forward into a steep grade, the abrupt change of grade could
cause you to lose control. If the front end begins to
bounce, ease off the throttle slightly to bring all four tires
back on the ground. As you approach the crest of the hill
ease off the throttle and slowly proceed over the top. If
the wheels start to slip as you approach the crest of a hill,
ease off the accelerator and maintain headway by turn-
ing the steering wheel no more than a ¼ turn quickly
back and forth. This will provide a fresh
biteinto the
surface and will usually provide enough traction to
complete the climb. If you do not make it to the top,
place the vehicle in REVERSE and back straight down
the grade using engine resistance along with the vehicle
brakes.
WARNING!
Never attempt to climb a hill at an angle or turn around
on a steep grade. Driving across an incline increases
the risk of a roll over, which may result in severe injury
or death.
• Driving Down Hill – Before driving down a steep hill
you need to determine if it is too steep for a safe descent.
What is the surface traction? Is the grade too steep to
maintain a slow controlled descent? Are there obstacles?
368 STARTING AND OPERATING