engine JEEP LIBERTY 2012 KK / 2.G Service Manual

AUTOMATIC TRANSMISSION
CAUTION!
Damage to the transmission may occur if the follow-
ing precautions are not observed:
•Shift into PARK only after the vehicle has come to
a complete stop.
•Shift into or out of REVERSE only after the
vehicle has come to a complete stop and the engine
is at idle speed.
•Do not shift between PARK, REVERSE, NEU-
TRAL, or DRIVE when the engine is above idle
speed.
•Before shifting into any gear, make sure your foot
is firmly pressing the brake pedal.
WARNING!
•Unintended movement of a vehicle could injure
those in or near the vehicle. As with all vehicles,
you should never exit a vehicle while the engine is
running. Before exiting a vehicle, always apply the
parking brake, shift the transmission into PARK,
and remove the ignition key. Once the key is
removed, the shift lever is locked in the PARK
position, securing the vehicle against unwanted
movement.
•When leaving the vehicle, always remove the key
fob from the ignition and lock your vehicle.(Continued)
322 STARTING AND OPERATING

WARNING! (Continued)
•Never leave children alone in a vehicle, or with
access to an unlocked vehicle. Allowing children
to be in a vehicle unattended is dangerous for a
number of reasons. A child or others could be
seriously or fatally injured. Children should be
warned not to touch the parking brake, brake
pedal or the shift lever.
•It is dangerous to move the shift lever out of PARK
or NEUTRAL if the engine speed is higher than
idle speed. If your foot is not firmly pressing the
brake pedal, the vehicle could accelerate quickly
forward or in reverse. You could lose control of the
vehicle and hit someone or something. Only shift
into gear when the engine is idling normally and
when your foot is firmly pressing the brake pedal.
Key Ignition Park Interlock
This vehicle is equipped with a Key Ignition Park Inter-
lock which requires the shift lever to be placed in PARK
before the ignition switch can be turned to the LOCK/
OFF position. The key can only be removed from the
ignition when the ignition is in the LOCK/OFF position.
Once the key is removed, the shift lever is locked in
PARK.
Brake/Transmission Shift Interlock System
This vehicle is equipped with a Brake Transmission Shift
Interlock (BTSI) that holds the shift lever in the PARK
position unless the brakes are applied. To move the shift
lever out of the PARK position, the ignition switch must
be turned to the ON/RUN or START position (engine
running or not) and the brake pedal must be pressed.5
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Four–Speed Automatic Transmission
The shift lever position display (located in the instrument
panel cluster) indicates the transmission gear range. You
must press the brake pedal to move the shift lever out of
the PARK position (refer to “Brake/Transmission Shift
Interlock System” in this section). To drive, move the shift
lever from PARK or NEUTRAL to the DRIVE position.
The electronically-controlled transmission provides a
precise shift schedule. The transmission electronics are
self-calibrating; therefore, the first few shifts on a new
vehicle may be somewhat abrupt. This is a normal
condition, and precision shifts will develop within a few
hundred miles (kilometers).
Shifting from DRIVE to PARK or REVERSE should be
done only after the accelerator pedal is released and the
vehicle is stopped. Be sure to keep your foot on the brake
pedal when moving the shift lever between these gears.
Gear Ranges
DO NOT race the engine when shifting from PARK or
NEUTRAL into another gear range.
Shift Lever
324 STARTING AND OPERATING

PARK
This range supplements the parking brake by locking the
transmission. The engine can be started in this range.
Never attempt to use PARK while vehicle is in motion.
Apply the parking brake when leaving vehicle in this
range.
When parking on a level surface, you may place the shift
lever in the PARK position first, and then apply the
parking brake.
When parking on a hill, apply the parking brake before
placing the shift lever in PARK, otherwise the load on the
transmission locking mechanism may make it difficult to
move the shift lever out of PARK. As an added precau-
tion, turn the front wheels toward the curb on a downhill
grade and away from the curb on an uphill grade.WARNING!
•Never use the PARK position as a substitute for
the parking brake. Always apply the parking
brake fully when parked to guard against vehicle
movement and possible injury or damage.
•Your vehicle could move and injure you and others
if it is not completely in PARK. Check by trying to
move the shift lever rearward (with the brake
pedal released) after you have placed it in PARK.
Make sure the transmission is in PARK before
leaving the vehicle.(Continued)
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WARNING! (Continued)
•It is dangerous to move the shift lever out of PARK
or NEUTRAL if the engine speed is higher than
idle speed. If your foot is not firmly pressing the
brake pedal, the vehicle could accelerate quickly
forward or in reverse. You could lose control of the
vehicle and hit someone or something. Only shift
into gear when the engine is idling normally and
when your foot is firmly pressing the brake pedal.(Continued)
WARNING! (Continued)
•Unintended movement of a vehicle could injure
those in or near the vehicle. As with all vehicles,
you should never exit a vehicle while the engine is
running. Before exiting a vehicle, always apply the
parking brake, shift the transmission into PARK,
and remove the ignition key. Once the key is
removed, the shift lever is locked in the PARK
position, securing the vehicle against unwanted
movement.
•When leaving the vehicle, always remove the key
fob from the ignition and lock your vehicle.(Continued)
326 STARTING AND OPERATING

WARNING! (Continued)
•Never leave children alone in a vehicle, or with
access to an unlocked vehicle. Allowing children
to be in a vehicle unattended is dangerous for a
number of reasons. A child or others could be
seriously or fatally injured. Children should be
warned not to touch the parking brake, brake
pedal or the shift lever.
CAUTION!
•Before moving the shift lever out of PARK, you
must turn the ignition switch from the LOCK/OFF
position to the ON/RUN position, and also press
the brake pedal. Otherwise, damage to the shift
lever could result.(Continued)
CAUTION! (Continued)
•DO NOT race the engine when shifting from
PARK or NEUTRAL into another gear range, as
this can damage the drivetrain.
The following indicators should be used to ensure that
you have engaged the shift lever into the PARK position:
•When shifting into PARK, move the shift lever all the
way forward and to the left until it stops and is fully
seated.
•Look at the shift lever position display and verify that
it indicates the PARK position.
•With brake pedal released, verify that the shift lever
will not move out of PARK.
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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 all forward gears. The
DRIVE position provides optimum driving characteris-
tics under all normal operating conditions.
328 STARTING AND OPERATING

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 TOW/HAUL mode,
or select the2range at lower speeds. Under these
conditions, using TOW/HAUL mode or the 2range
will improve performance and extend transmission life
by reducing excessive shifting and heat buildup.
If the transmission operating temperature exceeds nor-
mal operating limits, the powertrain controller will
modify the transmission shift schedule and expand the
range of torque converter clutch engagement. This is
done to prevent transmission damage due to overheat-
ing.
If the transmission becomes extremely hot, the “Trans-
mission Temperature Warning Light” may illuminate and
the transmission may downshift out of Overdrive until
the transmission cools down. During cold temperatures, transmission operation may
be modified depending on engine and transmission
temperature as well as vehicle speed. This feature im-
proves warm up time of the engine and transmission to
achieve maximum efficiency. Engagement of the torque
converter clutch is inhibited until the transmission fluid
is warm (refer to the “Note” under “Torque Converter
Clutch” in this section). During extremely cold tempera-
tures (-16°F [-27°C] or below), operation may briefly be
limited to second gear only. Normal operation will re-
sume once the transmission temperature has risen to a
suitable level.
2 (Second)
This range is used for moderate grades and to assist
braking on dry pavement or in mud and snow. Begins at
a stop in low gear with automatic upshift into second
gear. Will not shift into third gear.
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1 (First)
This range is used for hard pulling at low speeds in mud,
sand, snow, or on steep grades. Begins and stays in low
gear with no upshift. Provides engine compression brak-
ing at low speeds.
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 second gear regardless of which forward gear is
selected. PARK, REVERSE, and NEUTRAL will continue
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 dam-
aging 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 ignition switch to the LOCK/OFF position.
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.
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.
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If the transmission cannot be reset, authorized dealer
service is required.
Overdrive Operation
The automatic transmission includes an electronically
controlled Overdrive (fourth 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,
•the transmission fluid has reached an adequate tem-
perature,
•the engine coolant has reached an adequate tempera-
ture,
•vehicle speed is sufficiently high,
•the driver is not heavily pressing the accelerator, and
•the TOW/HAUL button has not been activated.
When To Use TOW/HAUL Mode
When driving in hilly areas, towing a trailer, carrying a
heavy load, etc., and frequent transmission shifting oc-
curs, press the TOW/HAUL switch to select TOW/
HAUL mode. This will improve performance and reduce
the potential for transmission overheating or failure due
to excessive shifting. When operating in TOW/HAUL
mode, the transmission will downshift into third gear.
5
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