engine JEEP WRANGLER 2012 JK / 3.G Workshop Manual

•With brake pedal released, verify that the shift lever
will not move out of PARK.
REVERSE
This range is for moving the vehicle backward. Shift into
REVERSE only after the vehicle has come to a complete
stop.
NEUTRAL
Use this range when the vehicle is standing for prolonged
periods with the engine running. The engine may be
started in this range. Set the parking brake and shift the
transmission into PARK if you must leave the vehicle.
WARNING!
Do not coast in NEUTRAL and never turn off the
ignition to coast down a hill. These are unsafe
practices that limit your response to changing traffic
or road conditions. You might lose control of the
vehicle and have a collision.
CAUTION!
Towing the vehicle, coasting, or driving for any other
reason with the transmission in NEUTRAL can result
in severe transmission damage. Refer to “Recre-
ational Towing” in “Starting And Operating” and
“Towing A Disabled Vehicle” in “What To Do In
Emergencies” for further information.
DRIVE
This range should be used for most city and highway
driving. It provides the smoothest upshifts and down-
shifts, and the best fuel economy. The transmission
automatically upshifts through underdrive first, second,
and third gears, direct fourth gear and overdrive fifth
gear. The DRIVE position provides optimum driving
characteristics under all normal operating conditions.
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When frequent transmission shifting occurs (such as
when operating the vehicle under heavy loading condi-
tions, in hilly terrain, traveling into strong head winds, or
while towing heavy trailers), use the Electronic Range
Select (ERS) feature (refer to “Electronic Range Select
(ERS)” in this section) to select a lower gear range. Under
these conditions, using a lower gear range will improve
performance and extend transmission life by reducing
excessive shifting and heat buildup.
Transmission Limp Home Mode
Transmission function is monitored electronically for
abnormal conditions. If a condition is detected that could
result in transmission damage, Transmission Limp Home
Mode is activated. In this mode, the transmission remains
in the current gear until the vehicle is brought to a stop.
After the vehicle has stopped, the transmission will
remain in second gear regardless of which forward gear
is selected. PARK, REVERSE, and NEUTRAL will con-
tinue to operate. The Malfunction Indicator Light (MIL)may be illuminated. Limp Home Mode allows the vehicle
to be driven to an authorized dealer for service without
damaging the transmission.
In the event of a momentary problem, the transmission
can be reset to regain all forward gears by performing the
following steps:
1. Stop the vehicle.
2. Shift the transmission into PARK.
3. Turn the engine OFF.
4. Wait approximately 10 seconds.
5. Restart the engine.
6. Shift into the desired gear range. If the problem is no
longer detected, the transmission will return to normal
operation.
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NOTE:Even if the transmission can be reset, we recom-
mend that you visit your authorized dealer at your
earliest possible convenience. Your authorized dealer has
diagnostic equipment to determine if the problem could
recur.
If the transmission cannot be reset, authorized dealer
service is required.
Electronic Range Select (ERS) Operation
The Electronic Range Select (ERS) shift control allows the
driver to limit the highest available gear when the shift
lever is in the DRIVE position. For example, if you shift
the transmission into 3 (third gear), the transmission will
never shift above third gear, but will shift down into
second and first gear normally.
You can switch between DRIVE and ERS mode at any
vehicle speed. When the shift lever is in the DRIVE
position, the transmission will operate automatically,
shifting between all available gears. Tapping the shift lever to the left (-) will downshift the transmission,
activate ERS mode, display the current gear in the
instrument cluster, and maintain that gear as the top
available gear. Once in ERS mode, tapping the shift lever
to the left (-) or right (+) will change the top available
gear.
To exit ERS mode, simply press and hold the shift lever to
the right (+) until “D” is once again displayed in the shift
lever position indicator in the instrument cluster.
WARNING!
Do not downshift for additional engine braking on a
slippery surface. The drive wheels could lose their
grip and the vehicle could skid, causing an accident
or personal injury.
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Screen Display1234D
Actual Gear(s) Allowed 1 1-2 1-3 1-4 1-5
NOTE: To select the proper gear position for maximum
deceleration (engine braking), tap the shift lever to the
left (-) repeatedly as the vehicle slows. The transmission
will shift to the range from which the vehicle can best be
slowed down.
Overdrive Operation
The automatic transmission includes an electronically
controlled Overdrive (fifth gear). The transmission will
automatically shift into the Overdrive gear if the follow-
ing conditions are present:
•the shift lever is in the DRIVE position,
•vehicle speed is sufficiently high, and
•the driver is not heavily pressing the accelerator.
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)
•4H (Four-wheel drive high range)
•N (Neutral)
•4L (Four-wheel drive low range)
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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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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 freshbiteand help maintain your momen-
tum.
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 before
entering 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
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provide a freshbiteinto 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.
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.
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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
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 are
designated and approved. You should tread lightly and
avoid damage to the environment. You should know
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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.CAUTION!
•Water ingestion into the axles, transmission, trans-
fer case, engine or vehicle interior can occur if you
drive too fast or through too deep of water. Water
can cause permanent damage to engine, driveline
or other vehicle components, and your brakes will
be less effective once wet and/or muddy.
•This vehicle is capable of crossing through water
at a depth of 30 inches (76 cm) at speeds no greater
than 5 mph (8 km/h). Water ingestion can occur
causing damage to your vehicle.
Before You Cross Any Type Of Water
As you approach any type of water, you need to deter-
mine if you can cross it safely and responsibly. If neces-
sary, get out and walk through the water or probe it with
a stick. You need to be sure of its depth, approach angle,
current and bottom condition. Be careful of murky or
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