engine JEEP WRANGLER 2011 JK / 3.G Workshop Manual

Overdrive can be locked out by pressing the O/D OFF
switch located on the center console. A indicator light in
the instrument cluster will illuminate to show that the
switch has been activated. When the indicator light is on,
Overdrive is locked out. Pressing the switch a secondtime restores the Overdrive function. The lockout feature
is useful when towing a trailer or carrying a heavy load.
If the transmission overheats, a “HOTOIL” message may
be displayed in the odometer (accompanied by a chime
sound). If the “HOTOIL” message turns on, stop the
vehicle and run the engine at idle or faster, with the
transmission in NEUTRAL until the message turns off.
WARNING!
If the Transmission Temperature “HOTOIL” Warn-
ing Message is illuminated and you continue operat-
ing the vehicle, in some circumstances you could
cause the fluid to boil over, come in contact with hot
engine or exhaust components and cause a fire.
O/D OFF Switch
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CAUTION!
Continuing to drive with the Transmission Tempera-
ture “HOTOIL” Warning Message illuminated will
eventually cause severe transmission damage or
transmission failure.
2 (Second)
This range is used for moderate grades and to assist
braking on dry pavement or in mud and snow. The
vehicle begins from a stop in low gear with automatic
upshift to second gear. The vehicle will not shift into
third gear.
1 (First)
This range is used for hard pulling at low speeds in mud,
sand, snow, or on steep grades. The vehicle begins and
stays in low gear with no upshift. This gear provides
engine compression braking at low speeds.
CAUTION!
•Before moving the shift lever out of PARK, you
must turn the ignition from LOCK so the steering
wheel and shift lever are released. Otherwise,
damage to the steering column or shift lever could
result.
•Never race the engine with the brakes on and the
vehicle in gear, and never hold the vehicle on an
incline without applying the brakes. These prac-
tices can overheat and damage the transmission.
•When “rocking” a stuck vehicle by moving be-
tween DRIVE and REVERSE, do not spin the
wheels faster than 15 mph (24 km/h), or drivetrain
damage may result.
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Transmission Limp Home Mode
Transmission function is monitored for abnormal condi-
tions. If a condition is detected that could result in
transmission damage, the Transmission Limp Home
Mode will be engaged. In this mode, the transmission
will operate (when in DRIVE) in second gear only.
To reset the transmission, use the following procedure:
1. Stop the vehicle.
2. Move the shift lever to the PARK position.
3. Turn OFF the engine and be sure to turn the key fob to
the LOCK position.
4. Wait approximately 10 seconds, then restart the en-
gine.
5. Move the shift lever to the desired gear range.
If the problem is no longer detected, the transmission will
return to normal operation. If the problem persists,PARK, REVERSE, and NEUTRAL will continue to oper-
ate. Only second gear will operate in the DRIVE position.
Have the transmission checked at your authorized dealer
as soon as possible.
Torque Converter Clutch
A feature designed to improve fuel economy has been
added to the automatic transmission of this vehicle. A
clutch within the torque converter engages automatically
at calibrated speeds. This may result in a slightly differ-
ent feeling or response during normal operation in high
gear. When the vehicle speed drops or during accelera-
tion, the clutch automatically and smoothly disengages.
FOUR–WHEEL DRIVE OPERATION
(COMMAND-TRAC I
OR ROCK-TRAC)
Operating Instructions/Precautions
The transfer case provides four mode positions:
•2H (Two-wheel drive high range)
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NOTE:Do not attempt to shift when only the front or
rear wheels are spinning. The transfer case is not
equipped with a synchronizer, and the front and rear
driveshaft speeds must be equal for a shift to take place.
Shifting while only the front or rear wheels are spinning
can cause damage to the transfer case.
When operating your vehicle in 4L, the engine speed will
be approximately three times (four times for Rubicon
models) that of the 2H or 4H positions at a given road
speed. Take care not to overspeed the engine.
Proper operation of four-wheel drive vehicles depends
on tires of equal size, type, and circumference on each
wheel. Any difference will adversely affect shifting and
cause damage to the transfer case.
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 N
(Neutral) position without first fully engaging the
parking brake. The transfer case N (Neutral) position
disengages both the front and rear driveshaft 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.
Shift Positions
For additional information on the appropriate use of each
transfer case mode position, see the information below:
2H Position
This range is used for normal street and highway driving
on hard-surfaced roads.
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WARNING!
On vehicles equipped with a limited-slip differen-
tial, never run the engine with one rear wheel off the
ground. The vehicle may drive through the rear
wheel remaining on the ground and cause you to lose
control of your vehicle.
AXLE LOCK (TRU–LOK) — RUBICON MODELS
The AXLE LOCK switch is located on the instrument
panel (to the left of the steering column).
This feature will only activate when the following con-
ditions are met:
•Key in ignition, vehicle in 4L (Low) range.
•Vehicle speed should be 10 mph (16 km/h) or less.
Axle Lock Switch
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WARNING!
Always wear your seat belt and firmly tie down
cargo. Unsecured cargo can become projectiles in an
off-road situation.
When To Use 4L (Low) Range
When off-road driving, shift into 4L (Low) for additional
traction and control on slippery or difficult terrain,
ascending or descending steep hills, and to increase low
speed pulling power. This range should be limited to
extreme situations such as deep snow, mud, steep in-
clines, or sand where additional low speed pulling power
is needed. Vehicle speeds in excess of 25 mph (40 km/h)
should be avoided when in 4L (Low) range.
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.
Driving In Snow, Mud And Sand
Snow
In heavy snow or for additional control and traction at
slower speeds, shift the transmission into a low gear and
the transfer case into 4L (Low) if necessary. Do not shift to
a lower gear than necessary to maintain headway. Over-
revving the engine can spin the wheels and traction will
be lost. If you start to slow to a stop, try turning your
steering wheel no more than a 1/4 turn quickly back and
forth, while still applying throttle. This will allow the
tires to get a fresh
biteand help maintain your momen-
tum.
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CAUTION!
On icy or slippery roads, do not downshift at high
engine RPM or vehicle speeds, because engine brak-
ing may cause skidding and loss of control.
Mud
Deep mud creates a great deal of suction around the tires
and is very difficult to get through. You should use
second gear (manual transmission), or DRIVE (automatic
transmission), with the transfer case in the 4L (Low)
position to maintain your momentum. If you start to slow
to a stop, try turning your steering wheel no more than a
1/4 turn quickly back and forth for additional traction.
Mud holes pose an increased threat of vehicle damage
and getting stuck. They are normally full of debris from
previous vehicles getting stuck. As a good practice beforeentering any mud hole, get out and determine how deep
it is, if there are any hidden obstacles and if the vehicle
can be safely recovered if stuck.
Sand
Soft sand is very difficult to travel through with full tire
pressure. When crossing soft, sandy spots in a trail,
maintain your vehicle’s momentum and do not stop. The
key to driving in soft sand is using the appropriate tire
pressure, accelerating slowly, avoiding abrupt maneu-
vers and maintaining the vehicle’s momentum. If you are
going to be driving on large soft sandy areas or dunes,
reduce your tire pressure to a minimum of 15 psi
(103 kPa) to allow for a greater tire surface area. Reduced
tire pressure will drastically improve your traction and
handling while driving on the soft sand, but you must
return the tires to normal air pressure before driving on
pavement or other hard surfaces. Be sure you have a way
to reinflate the tires prior to reducing the pressure.
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Before Climbing A Steep Hill
As you approach a hill, consider its grade or steepness.
Determine if it is too steep. Look to see what the traction
is on the hill side trail. Is the trail straight up and down?
What is on top and the other side? Are there ruts, rocks,
branches or other obstacles on the path? Can you safely
recover the vehicle if something goes wrong? If every-
thing looks good and you feel confident, shift the trans-
mission into a lower gear with 4L (Low) engaged, and
proceed with caution, maintaining your momentum as
you climb the hill.
Driving Up Hill
Once you have determined your ability to proceed and
have shifted into the appropriate gear, line your vehicle
up for the straightest possible run. Accelerate with an
easy constant throttle and apply more power as you start
up the hill. Do not race forward into a steep grade; the
abrupt change of grade could cause you to lose control. If
the front end begins to bounce, ease off the throttleslightly to bring all four tires back on the ground. As you
approach the crest of the hill, ease off the throttle and
slowly proceed over the top. If the wheels start to slip as
you approach the crest of a hill, ease off the accelerator
and maintain headway by turning the steering wheel no
more than a 1/4 turn quickly back and forth. This will
provide a fresh
biteinto the surface and will usually
provide enough traction to complete the climb. If you do
not make it to the top, place the vehicle in REVERSE and
back straight down the grade using engine resistance
along with the vehicle brakes.WARNING!
Never attempt to climb a hill at an angle or turn
around on a steep grade. Driving across an incline
increases the risk of a rollover, which may result in
severe injury.
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Driving Downhill
Before driving down a steep hill, you need to determine
if it is too steep for a safe descent. What is the surface
traction? Is the grade too steep to maintain a slow,
controlled descent? Are there obstacles? Is it a straight
descent? Is there plenty of distance at the base of the hill
to regain control if the vehicle descends to fast? If you feel
confident in your ability to proceed, then make sure you
are in 4L (Low) and proceed with caution. Allow engine
braking to control the descent and apply your brakes, if
necessary, but do not allow the tires to lock.
WARNING!
Do not descend a steep grade in NEUTRAL. Use
vehicle brakes in conjunction with engine braking.
Descending a grade too fast could cause you to lose
control and be seriously injured.
Driving Across An Incline
If at all possible, avoid driving across an incline. If it is
necessary, know your vehicle’s abilities. Driving across
an incline places more weight on the downhill wheels,
which increases the possibilities of a downhill slide or
rollover. Make sure the surface has good traction with
firm and stable soils. If possible, transverse the incline at
an angle heading slightly up or down.
WARNING!
Driving across an incline increases the risk of a
rollover, which may result in severe injury.
If You Stall Or Begin To Lose Headway
If you stall or begin to lose headway while climbing a
steep hill, allow your vehicle to come to a stop and
immediately apply the brake. Restart the engine and shift
into REVERSE. Back slowly down the hill allowing
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engine braking to control the descent and apply your
brakes, if necessary, but do not allow the tires to lock.
WARNING!
If the engine stalls or you lose headway or cannot
make it to the top of a steep hill or grade, never
attempt to turn around. To do so may result in
tipping and rolling the vehicle, which may result in
severe injury. Always back carefully straight down a
hill in REVERSE gear. Never back down a hill in
NEUTRAL using only the vehicle brakes. Never
drive diagonally across a hill; always drive straight
up or down.
Driving Through Water
Extreme care should be taken crossing any type of water.
Water crossings should be avoided, if possible, and only
be attempted when necessary in a safe, responsible
manner. You should only drive through areas which aredesignated and approved. You should tread lightly and
avoid damage to the environment. You should know
your vehicle’s abilities and be able to recover it if
something goes wrong. You should never stop or shut a
vehicle off when crossing deep water unless you ingested
water into the engine air intake. If the engine stalls, do
not attempt to restart it. Determine if it has ingested
water first. The key to any crossing is low and slow. Shift
into first gear (manual transmission), or DRIVE (auto-
matic transmission), with the transfer case in the 4L
(Low) position and proceed very slowly with a constant
slow speed {3 to 5 mph (5 to 8 km/h) maximum} and
light throttle. Keep the vehicle moving; do not try to
accelerate through the crossing. After crossing any water
higher than the bottom of the axle differentials, you
should inspect all of the vehicle fluids for signs of water
ingestion.
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