4 wheel drive Ram 2500 2011 Service Manual

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 rear wheels to pull errati-
cally 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.).
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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.
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
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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.
•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.
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The foot operated parking brake is located below the
lower left corner of the instrument panel. To apply the
park brake, firmly push the park brake pedal fully. To
release the parking brake, pull the parking brake release
handle.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
Parking Brake Release
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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.
3500 Dual Rear Wheel Models Only
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 Sys-
tem (ABS), Traction Control System (TCS), Brake Assist
System (BAS), Hill Start Assist (HSA), Electronic Stability
Control (ESC) and Trailer Sway Control (TSC). 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 ABS aids the driver in maintaining vehicle control
under adverse braking conditions. The system controls
hydraulic brake pressure to prevent wheel lockup and
help avoid skidding on slippery surfaces during braking.
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NOTE:ABS improves steering control of the vehicle
during hard braking maneuvers.
WARNING!
•ABS cannot prevent the natural laws of physics
from acting on the vehicle, nor can it increase
braking or steering efficiency beyond that af-
forded 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 hydro-
planing.
•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.
Traction Control System (TCS) – If Equipped
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
traction.
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WARNING! (Continued)
•HSA is not a parking brake. If you stop the vehicle
on a hill without putting the transmission in
PARK or using the parking brake, it will roll down
the incline and could cause a collision with an-
other vehicle or object. Always remember to use
the parking brake while parking on a hill and that
the driver is responsible for braking the vehicle.
HSA Off
Non-EVIC Equipped Vehicles
If you wish to turn off the HSA system, follow this
procedure:
1. Start with the engine OFF, and the vehicle in PARK
with the wheels straight.
2. Start the engine.3. With the engine running and the brake applied, rotate
the steering wheel 180° counterclockwise from center.
4. Press the “ESC Off” switch four times within 20 sec-
onds. The “ESC Off Indicator Light” should appear and
disappear four times.
5. Rotate the steering wheel 360° clockwise (180° clock-
wise from center).
6. Cycle ignition switch OFF then ON.
7. If the sequence was completed properly, the “ESC Off
Indicator Light” will blink several times to confirm HSA
is off.
Steps 1 through 7 must be completed within 90 seconds
to turn off HSA. Repeat steps 1 through 7 to re-enable
HSA functionality.
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EVIC Equipped Vehicles
HSA is a Customer Programmable Feature on a EVIC
equipped vehicle. If you wish to turn off the HSA feature,
refer to “Electronic Vehicle Information Center (EVIC)/
Customer Programmable Features” in “Understanding
Your Instrument Panel” for further information.
Electronic Stability Control (ESC) – If Equipped
The ESC system enhances directional control and stabil-
ity of the vehicle under various driving conditions. ESC
corrects for oversteering or understeering of the vehicle
by applying the brake of the appropriate wheel to assist
in counteracting the oversteer or understeer condition.
Engine power may also be reduced to help the vehicle
maintain the desired path.
ESC uses sensors in the vehicle to determine the vehicle
path intended by the driver and compares it to the actual
path of the vehicle. When the actual path does not matchthe intended path, ESC applies the brake of the appro-
priate wheel to assist in counteracting the oversteer or
understeer condition.
•Oversteer - when the vehicle is turning more than
appropriate for the steering wheel position.
•Understeer - when the vehicle is turning less than
appropriate for the steering wheel position.
All Two-Wheel Drive Vehicles and Four-Wheel
Drive Vehicles in 2WD, 4WD AUTO, or 4WD
LOCK Modes Can Choose the Following ESP
Operating Modes:
ESC On
This is the normal operating mode for ESC in 2WD/4WD
AUTO/4WD LOCK modes and in 2WD vehicles. When-
ever the vehicle is started or the transfer case (if
equipped) is shifted from 4WD LOW or Neutral, back to
4WD LOCK or 4WD AUTO, the ESC system will be in
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All Four-Wheel Drive Vehicles in 4WD AUTO and
4WD LOCK Modes Can Also Choose the
Following ESC Operating Mode. This is the Only
ESC Operating Mode in 4WD LOW:
Full Off
This mode is intended for off-road use when ESC stabil-
ity features could inhibit vehicle maneuverability due to
trail conditions. This mode is entered by pressing and
holding the “ESC Off” switch for five seconds when the
vehicle is stopped and the engine is running. After five
seconds, the “ESP Off Indicator Light” will illuminate
and the “ESC Off” message will appear in the odometer.
Press and release the trip odometer button located on the
instrument cluster to clear this message.
NOTE:The “ESC OFF” message will display and the
audible chime will sound when the shift lever is placedinto the PARK position from any other position and then
moved out of the PARK position. This will occur even if
the message was previously cleared.
In this mode, ESC and TCS except for the “limited slip”
feature described in the TCS section are turned off until
the vehicle reaches a speed of 40 mph (64 km/h). At
40 mph (64 km/h) the system returns to “Partial Off”
mode, described above. When the vehicle speed drops
below 35 mph (56 km/h) the ESC system shuts off. ESC
is off at low vehicle speeds so that it will not interfere
with off-road driving but ESC function returns to provide
the stability feature at speeds above 40 mph (64 km/h).
The “ESC Off Indicator Light” will always be illuminated
when ESC is off. To turn ESC on again, momentarily
press the “ESC Off” switch. This will restore the normal
“ESC On” mode of operation.
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Malfunction Indicator Light” begins to flash during ac-
celeration, ease up on the accelerator and apply as little
throttle as possible. Be sure to adapt your speed and
driving to the prevailing road conditions.
NOTE:
•The “ESC Activation/Malfunction Indicator Light”
and the “ESC OFF Indicator Light” come on momen-
tarily each time the ignition switch is turned ON.
•Each time the ignition is turned ON, the ESC system
will be ON even if it was turned off previously.
•The ESC system will make buzzing or clicking sounds
when it is active. This is normal; the sounds will stop
when ESC becomes inactive following the maneuver
that caused the ESC activation.
The “ESC OFF Indicator Light” indicates the
Electronic Stability Control (ESC) is off.
Trailer Sway Control (TSC) – If Equipped
The TSC system uses sensors in the vehicle to recognize
an excessively swaying trailer and will take the appro-
priate actions to attempt to stop the sway. The system
may reduce engine power and apply the brake of the
appropriate wheel(s) to counteract the sway of the trailer.
TSC will become active automatically once an excessively
swaying trailer is recognized. No driver action is re-
quired. Note that TSC cannot stop all trailers from
swaying. Always use caution when towing a trailer and
follow the trailer tongue weight recommendations. Refer
to “Trailer Towing” in “Starting and Operating” for
further information. When TSC is functioning, the “ESP
Off Indicator Light” will flash, the engine power may be
reduced and you may feel the brakes being applied to
individual wheels to attempt to stop the trailer from
swaying. TSC is disabled when the ESC system is in the
“Partial Off” or “Full Off” modes.
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