4 wheel drive Ram 1500 2015 Repair Manual

WARNING!
Do not disconnect the stabilizer bar and drive on
hard surfaced roads or at speeds above 18 mph
(29 km/h), you may lose control of the vehicle, which
could result in serious injury or death. The front
stabilizer bar enhances vehicle stability and is nec-
essary for maintaining control of the vehicle. The
system monitors vehicle speed and will attempt to
reconnect the stabilizer bar at speeds over 18 mph
(29 km/h). This is indicated by a flashing off road
light and solid on road light. Once vehicle speed is
reduced below 14 mph (22 km/h), the system will
attempt to return to the Off-Road mode.
To disconnect the stabilizer/sway bar, shift to either 4HI
or 4LO as shown in “Four Wheel Drive Operation” and
press the right hand Off Road stabilizer/sway bar button
to obtain the Off-Road position. The amber indicator
light will flash until the stabilizer/sway bar has been
fully disconnected.
NOTE:The stabilizer/sway bar may be torque locked due
to left and right suspension height differences. This condi-
tion is due to driving surface differences or vehicle loading.
In order for the stabilizer/sway bar to disconnect/
reconnect, the right and left halves of the bar must be
aligned. This alignment may require that the vehicle be
driven onto level ground or rocked from side to side.
To return to the On-Road mode; press the left hand On
Road stabilizer/sway bar button .
WARNING!
If the stabilizer/sway bar will not return to On-Road
mode, vehicle stability is greatly reduced. Do not
(Continued)
532 STARTING AND OPERATING

WARNING!(Continued)
attempt to drive the vehicle over 18 mph (29 km/h).
Driving faster than 18 mph (29 km/h) may cause loss
of control of the vehicle, which could result in
serious injury or death. Contact your local service
center for assistance.
SAFE OFF-ROAD DRIVING — POWER WAGON
ONLY
Off-Road Driving Tips And Vehicle Characteristics
Your vehicle has excellent on and off-road capabilities.
These off-road capabilities will allow you to explore
those wilderness trails where few travel, providing a
source of exciting and satisfying recreation. Before you
venture out, you should contact your local governmental
agency to determine the designated off-road vehicle
(ORV) trails or recreation areas. You should always tread
lightly and only use established roads, trails or ORV
recreational areas. The National Forest Service, Bureau of
Land Management or local Department of Natural Re-
sources are a wealth of information and usually have
maps with marked trails.
Skid Plates And Underbody Protection
Steel skid plates protect the major driveline components
of the truck including the fuel tank, transfer case and
steering damper. In addition, this vehicle is equipped
with boxed cross members and fore/aft rails. This addi-
tional protection allows the vehicle to be utilized in
severe off-road situations that would be considered im-
passable by a normal truck.
Ramp Travel Index (RTI)
The ramp travel index is the distance, in inches, that you
can drive your vehicle with one wheel on a 20-degree
ramp without lifting any other wheel off the ground. This
distance up the ramp divided by the wheelbase of the
vehicle and multiplied by 1,000 is the RTI. This vehicle
5
STARTING AND OPERATING 533

has an RTI of 510, which means you can articulate one
front wheel 26 inches in the air while the other three
wheels remain in contact with the ground.
Water Fording Characteristics
Water fording characteristic is the vehicle’s ability to
cross a body of still water, where the powertrain and
drivetrain are safe from water ingestion. This vehicle has
high water fording characteristics with the ability to cross
a pool of water, without stopping, 24 inches deep at a
maximum speed of 10 mph (16 km/h) and a pool of
water 30 inches deep at a maximum speed of 5 mph
(8 km/h), both with an entrance ramp angle of 1.3
degrees.
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
534 STARTING AND OPERATING

off-road driving without the ability to recover your
vehicle from a situation. Having another vehicle with
you usually works best for most situations. The first
thing to do is assess the situation. Why are you stuck?
Are you hung up on something? Would it be easier to go
forward or to go backward? Can you still move the
vehicle? Is there an anchor point to winch to? Are you
alone or do you have another vehicle to help? Is there
high risk of vehicle damage during the recovery process?
Answering these questions will help you determine the
best method of recovery. If you can still move the vehicle
slightly and the only issue is slick ground, then rock
cycling your vehicle would be the first choice. If you have
ample room, an additional vehicle and there is low risk of
vehicle impingement on the surroundings, then using a
tow strap to the vehicle tow hooks would be fast and
easy. If the vehicle is severely hung up or in a situation
where great care needs to be taken during the recovery,
then nothing can do the job better than a winch. If you are
severely hung up on something you should jack the
vehicle up and stack something under the wheels to
allow the vehicle to roll off the object without causing
further damage. This should be tried before attempting
any recovery method.
CAUTION!
Pulling the vehicle off an obstacle, without first
clearing the object, may result in additional under-
body damage.
•Rock Cycling Your Vehicle– Rock cycling your ve-
hicle is one of the easiest, fastest and most commonly
used methods. This simply involves shifting your
vehicle from DRIVE to REVERSE, while applying
throttle after each shift. During this process, for addi-
tional traction, try turning your steering wheel quickly
left and right no more than a¼turn. If you are stuck
in mud, sand, or snow try spinning your tires during
546 STARTING AND OPERATING

•Inspect the radiator for mud and debris and clean as
required.
•Check threaded fasteners for looseness, particularly on
the chassis, drivetrain components, steering, and sus-
pension. 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.
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.
•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.
550 STARTING AND OPERATING

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
turn.
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
5
STARTING AND OPERATING 551

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 diago-
nally 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.
•Check threaded fasteners for looseness, particularly on
the chassis, drivetrain components, steering, and sus-
pension. 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.
5
STARTING AND OPERATING 555

When the parking brake is applied with the ignition
switch ON, the “Brake Warning Light” in the instrument
cluster will illuminate.
NOTE:
•When the parking brake is applied and the transmis-
sion is placed in gear, the “Brake Warning Light” will
flash. If vehicle speed is detected, a chime will sound
to alert the driver. Fully release the parking brake
before attempting to move the vehicle.
•This light only shows that the parking brake is ap-
plied. It does not show the degree of brake application.
When parking on a hill, it is important to turn the front
wheels toward the curb on a downhill grade and away
from the curb on an uphill grade. Apply the parking
brake before placing the shift lever in PARK, otherwise
the load on the transmission locking mechanism may
make it difficult to move the shift lever out of PARK. The
parking brake should always be applied whenever the
driver is not in the vehicle.
Parking Brake Release
5
STARTING AND OPERATING 579

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 steering system. 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 System
(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 various driving conditions,
and are commonly referred to as ESC.
Anti-Lock Brake System (ABS)
The Four-Wheel Anti-Lock Brake System (ABS) is de-
signed to aid the driver in maintaining vehicle control
under adverse braking conditions. The system operates
5
STARTING AND OPERATING 581

WARNING!(Continued)
•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 functions similarly to a
limited-slip differential and 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 trac-
tion.
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
applies optimum pressure to the brakes. The system
5
STARTING AND OPERATING 583