traction control Ram 3500 2015 User Guide

CAUTION!
The door sill height is 25 inches. Water may intrude
into the interior of the vehicle at greater depths.
Simultaneous Brake And Throttle Operation
Many off-road driving conditions require the simultane-
ous use of the brake and throttle (two footed driving).
When climbing rocks, logs, or other stepped objects,
using light brake pressure with light throttle will keep the
vehicle from jerking or lurching. This technique is also
used when you need to stop and restart a vehicle on a
steep incline.
The Basics Of Off-Road Driving
You will encounter many types of terrain driving off-
road. You should be familiar with the terrain and area
before proceeding. There are many types of surface
conditions: hard packed dirt, gravel, rocks, grass, sand,mud, snow and ice. Every surface has a different effect on
your vehicle’s steering, handling and traction. Control-
ling your vehicle is one of the keys to successful off-road
driving, so always keep a firm grip on the steering wheel
and maintain a good driving posture. Avoid sudden
accelerations, turns or braking. In most cases there are no
road signs, posted speed limits or signal lights. Therefore
you will need to use your own good judgment on what is
safe and what isn’t. When on a trail you should always be
looking ahead for surface obstacles and changes in
terrain. The key is to plan your future driving route while
remembering what you are currently driving over.
CAUTION!
Never park your vehicle over dry grass or other
combustible materials. The heat from your vehicle
exhaust system could cause a fire.
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WARNING!
Always wear your seat belt and firmly tie down
cargo. Unsecured cargo can become projectiles in an
off-road situation.
When To Use Low Range
When driving off-road, shift into 4L (Low Range) for
additional traction or to improve handling and control on
slippery or difficult terrain. Due to the lower gearing, low
range will allow the engine to operate in a higher power
range. This will allow you to idle over obstacles and
down hills, with improved control and less effort. Also,
use 4L (Low Range) in rain, ice, snow, mud, sand, to get
heavy loads rolling, improve traction, or whenever 4H
(High Range) traction will not do the job.
Driving In Snow, Mud And Sand
There is a drastic reduction in traction when driving in
snow, mud or sand. The vehicle will be less responsive to
steering, acceleration and braking inputs. Therefore you
should accelerate slowly, leave greater stopping distances
and avoid abrupt vehicle maneuvers. You want to keep a
slow constant steady pace. The key is to maintain the
vehicle’s momentum.
•Snow – In heavy snow or for additional control and
traction at slower speeds, shift the transmission to a
low gear and shift the transfer case to 4L (Low Range)
if necessary. Do not shift to a lower gear than necessary
to maintain headway. Over-revving the engine can
spin the wheels and traction will be lost. If you start to
slow to a 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 fresh
bite and help maintain your momentum.
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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 4L (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 mo-
mentum. 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.
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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 trans-
mission into a lower gear, shift the transfer case into 4L
(Low) and proceed with caution. You should use first
gear and 4L (Low Range) for very steep hills. •
Driving Up Hill – Once you have determined your
ability to proceed and have shifted into the appropri-
ate gear, line your vehicle up for the straightest pos-
sible 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 turning the steering wheel no more than
a ¼ turn quickly back and forth. This will provide a
fresh bite into 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.
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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? Is it a straight descent? Is there plenty of
distance at the base of the hill to regain control if the
vehicle descends too fast? If you feel confident in your
ability to proceed then make sure you are in 4L (Low
Range) with the transmission in first gear (manually
select first gear on automatic transmissions) and pro-
ceed with caution. Allow engine braking to control the
descent and apply your brakes if necessary, but do not
allow the tires to lock.
WARNING!
Do not descend a steep grade in NEUTRAL. Use
vehicle brakes in conjunction with engine braking.
Descending a grade too fast could cause you to lose
control and be seriously injured or killed.
• Driving Across An Incline – If at all possible avoid
driving across an incline. If it is necessary, know your
vehicle’s abilities. Driving across an incline places
more weight on the down hill wheels, which increases
the possibilities of a down hill slide or rollover. Make
sure the surface has good traction with firm and stable
soils. If possible transverse the incline at an angle
heading slightly up or down.
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the water is deep enough to push on the large surface
area of the vehicle’s body. Before you proceed determine
the speed of the current, the water’s depth, approach
angle, bottom condition and if there are any obstacles,
then cross at an angle heading slightly upstream using
the low and slow technique.
WARNING!
Never drive through fast moving deep water. It can
push your vehicle downstream, sweeping it out of
control. This could put you and your passengers at
risk of injury or drowning.
Airing Down For Off-Road Driving
Running lower tire pressure off-road can improve your
ride comfort and vehicle traction. Reducing the tire air
pressure allows the tire to bulge slightly, improving itssurface area for better flotation and ability to mold or form
to the ground contour. Different terrain, tires, and vehicles
require different tire pressure. Hard surfaces like rock and
heavier vehicles require higher pressures than softer sur-
faces such as sand and lighter vehicles. You will need to
experiment to determine what is right for your situation. It
is easier and faster to let air out than it is to replace it so,
start high and lower it as required. Remember you must
return the tires to normal air pressure before driving on
road or at highway conditions. Be sure you have a way to
return the tires to their normal on road air pressure.
CAUTION!
Reduced tire pressure increases the risk of tire dam-
age and may cause tire unseating with total loss of air
pressure. To reduce the risk of tire unseating, while at
a reduced tire pressure, drive at slower speeds and
avoid sharp turns or abrupt maneuvers.
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•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 imbalance 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 per-
forms similarly to a conventional differential. On slip-
pery 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 application 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.
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.
Care should be taken to avoid sudden accelerations 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
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DRIVING ON SLIPPERY SURFACES
Acceleration
Rapid acceleration on snow covered, wet, or other slip-
pery surfaces may cause the driving wheels to pull
erratically to the right or left. This phenomenon occurs
when there is a difference in the surface traction under
the rear (driving) wheels.
WARNING!
Rapid acceleration on slippery surfaces is dangerous.
Unequal traction can cause sudden pulling of the rear
wheels. You could lose control of the vehicle and
possibly have a collision. Accelerate slowly and
carefully whenever there is likely to be poor traction
(ice, snow, wet mud, loose sand, etc.).
Traction
When driving on wet or slushy roads, it is possible for a
wedge of water to build up between the tire and road
surface. This is known as hydroplaning and may cause
partial or complete loss of vehicle control and stopping
ability. To reduce this possibility, the following precau-
tions should be observed:
•Slow down during rainstorms or when the roads are
slushy.
• Slow down if the road has standing water or puddles.
• Replace tires when tread wear indicators first become
visible.
• Keep tires properly inflated.
• Maintain sufficient distance between your vehicle and
the vehicle in front of you to avoid a collision in a
sudden stop.
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BRAKE SYSTEM
If power assist is lost for any reason (for example,
repeated brake applications with the engine off), the
brakes will still function. However, you will experience a
substantial increase in braking effort to stop the vehicle.
If either the front or rear hydraulic system loses normal
braking capability, the remaining system will still func-
tion with some loss of overall braking effectiveness. This
will be evident by increased pedal travel during applica-
tion, greater pedal force required to slow or stop, and
activation of the “Brake Warning Light” and the “ABS
Warning Light” (if equipped) during brake use.
Hydraulic Brake Assist — 2500/3500 Models Only
(Except Power Wagon)
The brake system power assist is provided by a hydro-
boost unit which shares fluid with the power steeringsystem. You may experience some clicking or hissing
noises from the hydro-boost system during hard braking
conditions.
NOTE:
Under cold temperatures, pedal effort will be
higher than normal until the power steering fluid reaches
operating temperature.
ELECTRONIC BRAKE CONTROL SYSTEM
Your vehicle is equipped with an advanced electronic
brake control system that includes Anti-Lock Brake Sys-
tem (ABS), Traction Control System (TCS), Brake Assist
System (BAS), Electronic Roll Mitigation (ERM), Hill
Start Assist (HSA), Electronic Stability Control (ESC),
Trailer Sway Control (TSC) and Hill Decent Control
(HDC [Power Wagon only]). All of the systems work
together to enhance vehicle stability and control in vari-
ous driving conditions, and are commonly referred to as
ESC.
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WARNING!(Continued)
efficiency beyond that afforded by the condition of
the vehicle brakes and tires or the traction afforded.
• The ABS cannot prevent collisions, including those
resulting from excessive speed in turns, following
another vehicle too closely, or hydroplaning.
• The capabilities of an ABS-equipped vehicle must
never be exploited in a reckless or dangerous
manner which could jeopardize the user’s safety or
the safety of others.
ABS Warning Light
The ABS includes an amber warning light. When the light
is illuminated, the ABS is not functioning. The system
reverts to standard, non-anti-lock brakes.
Traction Control System (TCS)
The TCS monitors the amount of wheel spin of each of
the driven wheels. If wheel spin is detected, brake pressure is applied to the slipping wheel(s), and engine
power is reduced to provide enhanced acceleration and
stability. A feature of the TCS system, Brake Limited
Differential (BLD), controls the wheel spin across a
driven axle. If one wheel on a driven axle is spinning
faster than the other, the system will apply the brake of
the spinning wheel. This will allow more engine torque
to be applied to the wheel that is not spinning. This
feature remains active even if TCS and ESC are in the
“Partial Off” mode. Refer to “Electronic Stability Control
(ESC)” in this section of this manual. This brake pressure
modulation transfers drive torque from slipping to non-
slipping wheels to provide optimal forward traction.
Brake Assist System (BAS)
The BAS is designed to optimize the vehicle’s braking
capability during emergency braking maneuvers. The
BAS detects an emergency braking situation by sensing
the rate and amount of brake application and then
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