wheel RAM CHASSIS CAB 2012 Service Manual

Electronically Shifted Transfer Case
(Four-Position Switch) – If Equipped
This is an electronic shift transfer case and is operated by
the 4WD Control Switch (Transfer Case Switch), which is
located on the instrument panel. This electronically shifted transfer case provides four
mode positions:
• Two-wheel drive high range (2WD)
• Four-wheel drive lock range (4WD LOCK)
• Four-wheel drive low range (4WD LOW)
• Neutral (NEUTRAL)
This electronically shifted transfer case is designed to be
driven in the two-wheel drive position (2WD) for normal
street and highway conditions on dry, hard surfaced
roads.
When additional traction is required, the transfer case
4WD LOCK and 4WD LOW positions can be used to lock
the front and rear driveshafts together, forcing the front
and rear wheels to rotate at the same speed. This is
accomplished by rotating the 4WD Control Switch to theTransfer Case Switch (Four-Position)292 STARTING AND OPERATING

2. The newly selected position indicator light will con-
tinue to flash.
3. The transfer case will not shift.
NOTE: Before retrying a selection, make certain that all
the necessary requirements for selecting a new transfer
case position have been met. To retry the selection, turn
the control knob back to the current position, wait five
seconds, and retry selection. To find the shift require-
ments, refer to the  Shifting Procedure  in this section for
further information.
The “SVC 4WD Warning Light” monitors the electronic
shift four-wheel drive system. If this light remains on
after engine start up or illuminates during driving, it
means that the four-wheel drive system is not function-
ing properly and that service is required. WARNING!Always engage the parking brake when powering
down the vehicle if the “SVC 4WD Warning Light” is
illuminated. Not engaging the parking brake may
allow the vehicle to roll, which may cause personal
injury.
NOTE: Do not attempt to make a shift while only the
front or rear wheels are spinning, as this can cause
damage to driveline components.
When operating your vehicle in 4WD LOW, the engine
speed is approximately three times that of the 2WD or
4WD LOCK positions at a given road speed. Take care
not to overspeed the engine and do not exceed 25 mph
(40 km/h).294 STARTING AND OPERATING

Proper operation of four-wheel drive vehicles depends
on tires of equal size, type and circumference on each
wheel. Any difference in tire size can cause damage to the
drivetrain.
Because four-wheel drive provides improved traction,
there is a tendency to exceed safe turning and stopping
speeds. Do not go faster than road conditions permit.
WARNING!You or others could be injured if you leave the
vehicle unattended with the transfer case in the
NEUTRAL position without first fully engaging the
parking brake. The transfer case NEUTRAL position
disengages both the front and rear driveshafts from
the powertrain and will allow the vehicle to move
regardless of the transmission position. The parking
brake should always be applied when the driver is
not in the vehicle. For additional information on the appropriate use of each
transfer case mode position, see the information below:
2WD
Rear Wheel Drive High Range - This range is for normal
street and highway driving on dry, hard surfaced roads.
4WD LOCK
Four-Wheel Drive Lock Range - This range locks the front
and rear driveshafts together forcing the front and rear
wheels to rotate at the same speed. This range provides
additional traction for loose, slippery road surfaces only.
4WD LOW
Four-Wheel Drive Low Range - This range provides low
speed four-wheel drive. It locks the front and rear
driveshafts together forcing the front and rear wheels to
rotate at the same speed. This range provides additional
traction and maximum pulling power for loose, slippery
road surfaces only. Do not exceed 25 mph (40 km/h).
5 STARTING AND OPERATING 295

NOTE: The four-wheel drive system will not allow
shifts between 2WD/4WD LOCK if the front and/or rear
wheels are spinning (no traction). In this situation, the
selected position indicator light will flash and the origi-
nal position indicator light will remain ON. At this time,
reduce speed and stop spinning the wheels to complete
the shift.
2WD or 4WD LOCK ⇔ 4WD LOW
NOTE: When shifting into or out of 4WD LOW some
gear noise may be heard. This noise is normal and is not
detrimental to the vehicle or occupants.
Shifting can be performed with the vehicle rolling 2 to
3 mph (3 to 5 km/h) or completely stopped. You can use
either of the following procedures:
Preferred Procedure
1. With the engine running, slow the vehicle to 2 to
3 mph (3 to 5 km/h). 2. Shift the transmission into NEUTRAL.
3. While still rolling, rotate the transfer case control
switch to the desired position.
4. After the desired position indicator light is ON (not
flashing), shift the transmission back into gear.
Alternate Procedure
1. Bring the vehicle to a complete stop.
2. With the ignition switch in the ON position, and the
engine either OFF or running, shift the transmission into
NEUTRAL.
3. Rotate the transfer case control switch to the desired
position.
4. After the desired position indicator light is ON (not
flashing), shift the transmission back into gear.
5 STARTING AND OPERATING 297

NOTE:
• If Steps 1 or 2 of either the Preferred or Alternate
Procedure are not satisfied prior to attempting the
shift, then the desired position indicator light will flash
continuously while the original position indicator light
is ON, until all requirements have been met.
• The ignition switch must be in the ON position for a
shift to take place and for the position indicator lights
to be operable. If the ignition switch is not in the ON
position, the shift will not take place and no position
indicator lights will be on or flashing.
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 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 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.298 STARTING AND OPERATING

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
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:
1. Slow down during rainstorms or when the roads are
slushy.
5 STARTING AND OPERATING 299

WARNING!• Driving through standing water limits your vehi-
cle’s traction capabilities. Do not exceed 5 mph
(8 km/h) when driving through standing water.
• Driving through standing water limits your vehi-
cle’s braking capabilities, which increases stop-
ping distances. Therefore, after driving through
standing water, drive slowly and lightly press on
the brake pedal several times to dry the brakes.
• Getting water inside your vehicle’s engine can
cause it to lock up and stall out, and leave you
stranded.
• Failure to follow these warnings may result in
injuries that are serious or fatal to you, your
passengers, and others around you. POWER STEERING
The standard power steering system will give you good
vehicle response and increased ease of maneuverability
in tight spaces. The system will provide mechanical
steering capability if power assist is lost.
If for some reason the power assist is interrupted, it will
still be possible to steer your vehicle. Under these condi-
tions, you will observe a substantial increase in steering
effort, especially at very low vehicle speeds and during
parking maneuvers.
NOTE:
• Increased noise levels at the end of the steering wheel
travel are considered normal and do not indicate that
there is a problem with the power steering system.
• Upon initial start-up in cold weather, the power steer-
ing pump may make noise for a short amount of time.
This is due to the cold, thick fluid in the steering302 STARTING AND OPERATING

system. This noise should be considered normal, and it
does not in any way damage the steering system.
WARNING!Continued operation with reduced power steering
assist could pose a safety risk to yourself and others.
Service should be obtained as soon as possible.
CAUTION!Prolonged operation of the steering system at the end
of the steering wheel travel will increase the steering
fluid temperature and it should be avoided when
possible. Damage to the power steering pump may
occur.
Power Steering Fluid Check
Checking the power steering fluid level at a defined
service interval is not required. The fluid should only be checked if a leak is suspected, abnormal noises are
apparent, and/or the system is not functioning as antici-
pated. Coordinate inspection efforts through an autho-
rized dealer.
CAUTION!Do not use chemical flushes in your power steering
system as the chemicals can damage your power
steering components. Such damage is not covered by
the New Vehicle Limited Warranty.
WARNING!Fluid level should be checked on a level surface and
with the engine off to prevent injury from moving
parts and to ensure accurate fluid level reading. Do
not overfill. Use only manufacturer’s recommended
power steering fluid.
5 STARTING AND OPERATING 303

NOTE:
• When the parking brake is applied and the automatic
transmission 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. For vehicles equipped
with an automatic transmission, 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. WARNING!• Never leave children alone in a vehicle. Leaving
unattended children in a vehicle is dangerous for a
number of reasons. A child or others could be
seriously or fatally injured.
• Do not leave the key fob in the vehicle. A child
could operate power windows, other controls, or
move the vehicle.
• Be sure the parking brake is fully disengaged
before driving; failure to do so can lead to brake
failure and a collision.
• Always fully apply the parking brake when leav-
ing your vehicle or it may roll and cause damage or
injury. Also, be certain to leave an automatic
transmission in PARK, a manual transmission in
REVERSE or first gear. Failure to do so may cause
the vehicle to roll and cause damage or injury.
5 STARTING AND OPERATING 305

Four-Wheel Anti-Lock Brake System
WARNING!The Four-Wheel Anti-Lock Brake System contains
sophisticated electronic equipment. It may be sus-
ceptible to interference caused by improperly in-
stalled or high output radio transmitting equipment.
This interference can cause possible loss of anti-lock
braking capability. Installation of such equipment
should be performed by qualified professionals.
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
with a separate computer to modulate hydraulic pressure
to prevent wheel lockup and help avoid skidding on
slippery surfaces. The system’s pump motor runs during an ABS stop to
provide regulated hydraulic pressure. The pump motor
makes a low humming noise during operation. This is
normal.
The ABS conducts a low-speed selftest at about 10 mph
(16 km/h). If you have your foot lightly on the brake
while this test is occurring, you may feel slight pedal
movement. The movement can be more apparent on ice
and snow. This is normal.
When you are in a severe braking condition involving
use of the ABS, you will experience some pedal drop as
the vehicle comes to a complete stop. This is the result of
the system reverting to the base brake system and is
normal.
Engagement of the ABS may be accompanied by a
pulsing sensation. You may also hear a clicking noise.
These occurrences are normal, and indicate that the
system is functioning. 5 STARTING AND OPERATING 307