wheel Ram 5500 Chassis Cab 2015 Repair Manual

modulation transfers drive torque from slipping to non-
slipping wheels to provide optimal forward traction.
Hill Start Assist (HSA)
The HSA system is designed to assist the driver in
launching a vehicle on an incline. HSA will maintain the
level of brake pressure the driver inputs for a short
duration once the driver takes his foot off of the brake
pedal. If the driver does not apply the throttle during this
short duration, the system will release brake pressure
and the vehicle will roll down the incline. The system will
release brake pressure in proportion to the amount of
throttle applied.
During operation, HSA will activate the brake control
system and a clicking noise may occur. If your foot is on
the brake pedal during operation you may feel a slight
pedal movement. The clicking and pedal movement is
normal and both will stop when HSA becomes inactive.
HSA Activation Criteria
The following criteria must be met in order for HSA to
activate:
•Vehicle must be stopped
• Vehicle must be on an approximate 7% or greater
incline
• Gear selection matches vehicle uphill direction (i.e.,
vehicle facing uphill is in forward gear; vehicle back-
ing uphill is in REVERSE gear).
WARNING!
There may be situations on minor hills with a loaded
vehicle or while pulling a trailer where the system
will not activate and slight rolling may occur, which
could cause a collision with another vehicle or object.
Always remember the driver is responsible for brak-
ing the vehicle.
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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 collide with another vehicle,
object or person, and cause serious or fatal injury.
Always remember to use the parking brake while
parking on a hill and that the driver is responsible
for braking the vehicle.
HSA Off
HSA is a Customer Programmable Feature in the EVIC/
DID. If you wish to turn off the HSA feature, refer to
“Electronic Vehicle Information Center (EVIC)/Driver
Information Display (DID)” in “Understanding Your
Instrument Panel” for further information.
Electronic Stability Control (ESC)
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 match
the 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.
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•Understeer - when the vehicle is turning less than
appropriate for the steering wheel position.
WARNING!
Electronic Stability Control (ESC) cannot prevent the
natural laws of physics from acting on the vehicle,
nor can it increase the traction afforded by prevailing
road conditions. ESC cannot prevent accidents, in-
cluding those resulting from excessive speed in
turns, driving on very slippery surfaces, or hydro-
planing. ESC also cannot prevent accidents resulting
from loss of vehicle control due to inappropriate
driver input for the conditions. Only a safe, attentive,
and skillful driver can prevent accidents. The capa-
bilities of an ESC equipped vehicle must never be
exploited in a reckless or dangerous manner which
could jeopardize the user ’s safety or the safety of
others.
All Two-Wheel Drive Vehicles And Four-Wheel
Drive Vehicles In 2WD, 4WD AUTO, Or 4WD
LOCK Modes Can Choose The Following ESC
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
this mode. This mode should be used for almost all
driving situations. ESC should only be turned to ESC
Partial Off or “ESC Full Off” for specific reasons as noted
below.
ESC Partial Off
This mode is entered by momentarily pressing the “ESC
Partial Off” switch. When in Partial Offmode, the TCS
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portion of ESC, except for the “limited slip” feature
described in the TCS section, has been disabled and the
ESC Off Indicator Lightwill be illuminated. All other
stability features of ESC function normally. This mode is
intended to be used if the vehicle is in deep snow, sand,
or gravel conditions and more wheel spin than TCS
would normally allow is required to gain traction. To
turn ESC on again, momentarily press the “ESC Off”
switch. This will restore the normal “ESC On” mode of
operation.
NOTE: To improve the vehicle’s traction when driving
with snow chains or starting off in deep snow, sand or
gravel, it may be desirable to switch to the “ESC Partial
Off” mode by pressing the “ESC Off” switch. Once the
situation requiring ESC to be switched to the “ESC Partial
Off” mode is overcome, turn ESC back on by momen-
tarily pressing the “ESC Off” switch. This may be done
while the vehicle is in motion.WARNING!
• When in “ESC Partial Off” mode, the TCS func-
tionality of ESC, (except for the limited slip feature
described in the TCS section), has been disabled
and the “ESC Off Indicator Light” will be illumi-
nated. When in “ESC Partial Off” mode, the engine
power reduction feature of TCS is disabled, and
the enhanced vehicle stability offered by the ESC
system is reduced.
• Trailer Sway Control (TSC) is disabled when the
ESC system is in the ESC Partial Offmode.
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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
Selectable ESC Operating Mode in 4WD LOW:
ESC 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 “ESC Off Indicator Light” will illuminate.
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 placed
into 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 “ESC Partial
Off” mode, described above. When the vehicle speed
drops below 35 mph (56 km/h) the ESC system reverts
back to
ESC Full 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 in ESC Partial
Off andESC Full Off. To turn ESC on again, momen-
tarily press the “ESC Off” switch. This will restore the
normal “ESC On” mode of operation.
“ESC Full Off” is the only operating mode for ESC in
4WD LOW. Whenever the vehicle is started in 4WD LOW
or the transfer case (if equipped) is shifted from 4WD
LOCK or NEUTRAL, to 4WD LOW, the ESC system will
be in this mode.
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Trailer Sway Control (TSC)
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 to activate. 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 “ESC
Activation/Malfunction 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 “ESC Partial Off” or “ESC Full Off”
modes.TSC is only active in the default “ESC On” mode. TSC
can be disabled by pressing the “ESC Off” switch and
entering “ESC Partial Off” mode. It is not active in the
“ESC Partial Off” or “ESC Full Off” modes. Refer to the
ESC portion of this section for an explanation of the
different ESC operating modes.
WARNING!
If TSC activates while driving, slow the vehicle
down, stop at the nearest safe location, and adjust the
trailer load to eliminate trailer sway.
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CAUTION!
Because of the reduced ground clearance, do not take
your vehicle through an automatic car wash with a
compact or limited-use temporary spare installed.
Damage to the vehicle may result.
Spare Tire Matching Original Equipped Tire And
Wheel — If Equipped
Your vehicle may be equipped with a spare tire and
wheel equivalent in look and function to the original
equipment tire and wheel found on the front or rear axle
of your vehicle. This spare tire may be used in the tire
rotation for your vehicle. If your vehicle has this option,
refer to an authorized tire dealer for the recommended
tire rotation pattern.
Compact Spare Tire — If Equipped
The compact spare is for temporary emergency use only.
You can identify if your vehicle is equipped with a
compact spare by looking at the spare tire description on
the Tire and Loading Information Placard located on the
driver ’s side door opening or on the sidewall of the tire.
Compact spare tire descriptions begin with the letter “T”
or “S” preceding the size designation. Example: T145/
80D18 103M.
T, S = Temporary Spare Tire
Since this tire has limited tread life, the original equip-
ment tire should be repaired (or replaced) and reinstalled
on your vehicle at the first opportunity.
Do not install a wheel cover or attempt to mount a
conventional tire on the compact spare wheel, since the
wheel is designed specifically for the compact spare tire.
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Do not install more than one compact spare tire and
wheel on the vehicle at any given time.
WARNING!
Compact spares are for temporary emergency use
only. With these spares, do not drive more than
50 mph (80 km/h). Temporary use spares have limited
tread life. When the tread is worn to the tread wear
indicators, the temporary use spare tire needs to be
replaced. Be sure to follow the warnings, which
apply to your spare. Failure to do so could result in
spare tire failure and loss of vehicle control.
Full Size Spare — If Equipped
The full size spare is for temporary emergency use only.
This tire may look like the originally equipped tire on the
front or rear axle of your vehicle, but it is not. This spare
tire may have limited tread life. When the tread is wornto the tread wear indicators, the temporary use full size
spare tire needs to be replaced. Since it is not the same as
your original equipment tire, replace (or repair) the
original equipment tire and reinstall on the vehicle at the
first opportunity.
Limited-Use Spare — If Equipped
The limited-use spare tire is for temporary emergency
use only. This tire is identified by a label located on the
limited-use spare wheel. This label contains the driving
limitations for this spare. This tire may look like the
original equipped tire on the front or rear axle of your
vehicle, but it is not. Installation of this limited-use spare
tire affects vehicle handling. Since it is not the same as
your original equipment tire, replace (or repair) the
original equipment tire and reinstall on the vehicle at the
first opportunity.
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WARNING!
Limited-use spares are for emergency use only. In-
stallation of this limited-use spare tire affects vehicle
handling. With this tire, do not drive more than the
speed listed on the limit-use spare wheel. Keep
inflated to the cold tire inflation pressures listed on
your Tire and Loading Information Placard located
on the driver ’s side B-Pillar or the rear edge of the
driver ’s side door. Replace (or repair) the original
equipment tire at the first opportunity and reinstall it
on your vehicle. Failure to do so could result in loss
of vehicle control.
Tire Spinning
When stuck in mud, sand, snow, or ice conditions, do not
spin your vehicle’s wheels above 30 mph (48 km/h) or
for longer than 30 seconds continuously without stop-
ping.Refer to “Freeing A Stuck Vehicle” in “What To Do In
Emergencies” for further information.
WARNING!
Fast spinning tires can be dangerous. Forces gener-
ated by excessive wheel speeds may cause tire dam-
age or failure. A tire could explode and injure some-
one. Do not spin your vehicle’s wheels faster than
30 mph (48 km/h) for more than 30 seconds continu-
ously when you are stuck, and do not let anyone near
a spinning wheel, no matter what the speed.
Tread Wear Indicators
Tread wear indicators are in the original equipment tires
to help you in determining when your tires should be
replaced.
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WARNING!
Tires and the spare tire should be replaced after six
years, regardless of the remaining tread. Failure to
follow this warning can result in sudden tire failure.
You could lose control and have a collision resulting
in serious injury or death.
Keep dismounted tires in a cool, dry place with as little
exposure to light as possible. Protect tires from contact
with oil, grease, and gasoline.
Replacement Tires
The tires on your new vehicle provide a balance of many
characteristics. They should be inspected regularly for
wear and correct cold tire inflation pressures. The manu-
facturer strongly recommends that you use tires equiva-
lent to the originals in size, quality and performance
when replacement is needed. Refer to the paragraph on
“Tread Wear Indicator.” Refer to the Tire and Loading Information placard or the Vehicle Certification Label for
the size designation of your tire. The Load Index and
Speed Symbol for your tire will be found on the original
equipment tire sidewall. See the Tire Sizing Chart ex-
ample found in the Tire Safety Information section of this
manual for more information relating to the Load Index
and Speed Symbol of a tire.
It is recommended to replace the two front tires or two
rear tires as a pair. Replacing just one tire can seriously
affect your vehicle’s handling. If you ever replace a
wheel, make sure that the wheel’s specifications match
those of the original wheels.
It is recommended you contact your authorized tire
dealer or original equipment dealer with any questions
you may have on tire specifications or capability. Failure
to use equivalent replacement tires may adversely affect
the safety, handling, and ride of your vehicle.
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