2008 DODGE DURANGO torque

Overdrive Operation
The overdrive automatic transmission contains an elec-
tronically controlled fourth and fifth (if equipped) speed
(Overdrive). The transmission will automatically shift
from Drive to Overdrive if the following conditions are
present:
²the transmission selector is in Drive;
²the engine coolant has reached normal operating tem-
perature;
²vehicle speed is above approximately 30 mph (48
km/h);
²the ªTOW/HAULº switch has not been activated;
²transmission has reached normal operating tempera-
ture.NOTE:If the vehicle is started in extremely cold tem-
peratures, the transmission may not shift into Overdrive
and will automatically select the most desirable gear for
operation at this temperature. Normal operation will
resume when the transmission fluid temperature has
risen to a suitable level. Refer also to the Note under
torque converter clutch, later in this section.
If the transmission temperature gets extremely hot, the
transmission will automatically select the most desirable
gear for operation at this temperature. If the transmission
temperature becomes hot enough the TRANS TEMP light
may illuminate and the transmission may downshift out
of Overdrive until the transmission cools down. After
cooldown, the transmission will resume normal opera-
tion.
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The transmission will downshift from Overdrive to Drive
if the accelerator pedal is fully depressed at vehicle
speeds above approximately 35 mph (56 km/h).
When To Use ªTOW/HAULº Mode
When driving in hilly areas, towing a trailer, carrying a
heavy load, etc., and frequent transmission shifting oc-
curs, press the ªTOW/HAULº button. This will improveperformance and reduce the potential for transmission
overheating or failure due to excessive shifting. When
operating in ªTOW/HAULº mode, 5th gear (if
equipped) is disabled and 2-3 and 3-4 shift patterns are
modified. Shifts into Overdrive (4th gear) are allowed
during steady cruise (for improved fuel economy) and
automatic closed-throttle downshifts to 3rd gear (for
improved braking) will occur during steady braking.
The ªTOW/HAULº light will illuminate in the instru-
ment cluster to indicate when the switch has been
activated. Pressing the switch a second time restores
normal operation. If the ªTOW/HAULº mode is desired,
the button must be pressed each time the engine is
started.
Torque Converter Clutch
A feature designed to improve fuel economy is included
in all automatic transmissions. A clutch within the torque
converter engages automatically at a calibrated speed at
280 STARTING AND OPERATING

light throttle. It engages at higher speeds under heavier
acceleration. This may result in a slightly different feeling
or response during normal operation in high gear. When
the vehicle speed drops below a calibrated speed, or
during acceleration, the clutch automatically and
smoothly disengages. The feature is operational in Over-
drive and in Drive.
NOTE:The torque converter clutch will not engage
until the transmission fluid and engine coolant are warm
[usually after 1-3 miles (1.6 - 4.8 km) of driving]. Because
the engine speed is higher when the torque converter
clutch is not engaged, it may seem as if the transmission
is not shifting into Overdrive when cold. This is normal.
Pressing the9TOW/HAUL9button will demonstrate that
the transmission is able to shift into and out of Overdrive.
NOTE:If the vehicle has not been driven in several
days, the first few seconds of operation after shifting the
transmission into gear may seem sluggish. This is due tothe fluid partially draining from the torque converter into
the transmission. This condition is normal and will not
cause damage to the transmission. The torque converter
will refill within five seconds of shifting from Park into
any other gear position.
FOUR-WHEEL DRIVE OPERATION
NV 140 Transfer Case Operating
Information/Precautions ± If Equipped
The NV 140 is a single speed (HI range only) transfer case
which provides convenient full-time 4±wheel drive. No
driver interaction is required. This transfer case divides
engine torque almost evenly with 48 percent of engine
torque to the front axle and 52 percent of engine torque to
the rear axle.
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
transfer case.
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TCS (Traction Control System)
This system 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 functions similar 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 ESP are in the
ªPartial Offº mode. Refer to ªESP (Electronic Stability
Program)º 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.
ERM (Electronic Roll Mitigation)
This system anticipates the potential for wheel lift by
monitoring the driver 's steering wheel input and the
speed of the vehicle. When ERM determines that the rate
of change of the steering wheel angle and vehicles speed
are sufficient to potentially cause wheel lift, it applies the
appropriate brake and may reduce engine power to
lessen the chance that wheel lift will occur. ERM will only
intervene during very severe or evasive driving maneu-
vers.
ERM can only reduce the chance of wheel lift occurring
during severe or evasive driving maneuvers. It can not
prevent wheel lift due to other factors such as road
conditions, leaving the roadway or striking objects or
other vehicles.
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4WD/4WD LOCK or 2WD Models
ON
This is the normal operating mode for ESP in 4WD LOCK
and in 2WD vehicles. Whenever the vehicle is started or
the transfer case (if equipped) is shifted from 4WD LOW
or neutral back to 4WD LOCK, the ESP system will be in
this mode. This mode should be used for most all driving
situations. ESP should only be turned to ªPartial Offº for
specific reasons as noted below.
This mode is entered by momentarily
depressing the ªESP OFFº Control
Switch. When in ªPartial Offº mode,
the engine management portion of
ESP has been desensitized, the thresh-
olds for ESP activation are raised, and
the ªESP/TCS Indicator Lightº will be
illuminated. This mode is intended to
be used if the vehicle is in deep snow, sand or gravelconditions and more wheel spin than ESP would nor-
mally allow is required to gain traction. TSC (Trailer
Sway Control) is not available when the system is in the
9Partial Off9mode. To turn ESP on again, momentarily
depress the ªESP-Control OFFº Control Switch. This will
restore the normal ªONº mode of operation. ESP always
operates under braking, even with the switch in the
OFF-position.
WARNING!
In the Partial Off mode, the engine torque reduction
and stability features are desensitized. Therefore, the
enhanced vehicle stability offered by ESP is
unavailable.
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 ªPartial Offº
Partial Off
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5

mode by pressing the ESP Control Switch. Once the
situation requiring ESP to be switched to the ªPartial Offº
mode is overcome, turn ESP on by momentarily depress-
ing the ªESP Control Switchº. This may be done with the
vehicle is in motion.
4WD LOW Range
Partial Off
This is the normal operating mode for ESP 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 ESP system will be in this
mode. In 4WD LOW, ESP function is desensitized until
the vehicle reaches a speed of 30 mph (48 km/h). At 30
mph (48 km/h) the normal ESP stability function returns
and the ESP/TCS Indicator Lightº turns off. When the
vehicle speed drops below 25 mph (40 km/h) the ESP
system goes back to Partial Off. ESP is desensitized at low
vehicle speeds in 4WD LOW so that it will not interferewith off road driving but ESP function returns to provide
the stability feature at speeds above 30 mph (48 km/h).
The ABS is in a special Off-Road mode that allows wheels
to lock at lower speeds if gravel is detected to shorten
stopping distances.
NOTE:When the vehicle is in 4WD LOW, a feature of
the ESP system remains active whether the ESP is on or
off. This feature functions similar to a limited slip differ-
ential and controls the wheel spin across an axle. If one
wheel on an axle is spinning faster than the other, the
system will apply the brake of the spinning wheel and
allow more engine torque to be applied to the wheel that
is not spinning.
302 STARTING AND OPERATING

WARNING!
In the Partial Off mode, the engine torque reduction
and stability features are desensitized. Therefore, the
enhanced vehicle stability offered by ESP is
unavailable.
ESP/BAS Warning Lamp and ESP/TCS Indicator
Light
The malfunction indicator for the ESP is combined with
the BAS indicator. The yellow ªESP/BAS Warning
Lampº and the yellow ªESP/TCS Indicator Lightº in the
instrument cluster both come on when the ignition
switch is turned to the ªONº position. They should both
go out with the engine running. If the ªESP/BAS Warn-
ing Lampº comes on continuously with the engine
running, a malfunction has been detected in either theESP or BAS system, or both. If this light remains on after
several ignition cycles, and the vehicle has been driven
several miles at speeds greater than 30 mph (48 km/h),
see your authorized dealer as soon as possible to have the
problem diagnosed and corrected.
NOTE:
²The ªESP Indicator Lightº and the ªESP/BAS Warning
Lampº come on momentarily each time the ignition
switch is turned ON.
²Each time the ignition is turned ON, the ESP System
will be ON even if it was turned off previously.
²The ESP Control System will make buzzing or clicking
sounds when it is active. This is normal; the sounds
will stop when ESP becomes inactive following the
maneuver that caused the ESP activation.
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WARNING!
Raising the vehicle higher than necessary can make
the vehicle unstable and cause an accident. It could
slip off the jack and hurt someone near it. Raise the
vehicle only enough to remove the tire.
5. Remove the wheel nuts and pull the wheel off. Install
the spare wheel and wheel nuts with the cone shaped end
of the nuts toward the wheel. Lightly tighten the nuts. To
avoid risk of forcing the vehicle off the jack, do not fully
tighten the nuts until the vehicle has been lowered.
NOTE:Do not oil wheel studs. For chrome wheels, do
not substitute with chrome plated wheel nuts.
6. Using the wheel wrench, finish tightening the nuts in
a crisscross pattern. Correct nut tightness is 135   10 ft.
lbs. (183   14 N´m) dynamic torque. If in doubt about the
correct tightness, have them checked with a torque
wrench by your dealer or at a service station.
WARNING!
A loose tire or jack thrown forward in a collision or
hard stop could injure someone in the vehicle. Al-
ways stow the jack, tools and the extra tire and wheel
in the places provided.
7. Remove wheel blocks. Do not install chrome or alu-
minum wheel center caps on the spare wheel. This may
result in cap damage.
8. Lower the jack to its fully closed position. Stow the
replaced tire, jack, and tools as previously described.
9. Adjust the tire pressure when possible.
NOTE:Do not oil wheel studs. For chrome wheels, do
not substitute with chrome plated wheel nuts.
WHAT TO DO IN EMERGENCIES 373
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