light JEEP WRANGLER 2012 JK / 3.G Repair Manual

NOTE:The air conditioning compressor will not engage
until the engine has been running for about 10 seconds.
•MAX A/C
For maximum cooling, turn on the A/C and recirculation
buttons at the same time.
•ECONOMY MODE
If economy mode is desired, press the A/C button to turn
OFF the indicator light and the A/C compressor. Then,
move the temperature control to the desired temperature.
Automatic Temperature Control (ATC) — If
Equipped
Automatic Temperature Control
358 UNDERSTANDING YOUR INSTRUMENT PANEL

▫Brake Assist System (BAS) .............. 420
▫ Hill Start Assist (HSA) ................ 420
▫ Electronic Roll Mitigation (ERM) ......... 424
▫ Electronic Stability Control (ESC) ......... 425
▫ ESC Activation/Malfunction Indicator Light
And ESC Off Indicator Light ............ 429
▫ Trailer Sway Control (TSC) ............. 430
▫ Hill Descent Control (HDC) – If Equipped . . 431
 Tire Safety Information ................. 432
▫ Tire Markings ....................... 432
▫ Tire Identification Number (TIN) ......... 436
▫ Tire Terminology And Definitions ......... 437
▫ Tire Loading And Tire Pressure .......... 438
Tires — General Information ............. 443
▫ Tire Pressure ....................... 443
▫ Tire Inflation Pressures ................ 444
▫ Tire Pressures For High-Speed Operation . . . 445
▫ Radial-Ply Tires ..................... 446
▫ Spare Tire Matching Original Equipped Tire
And Wheel – If Equipped .............. 446
▫ Compact Spare Tire – If Equipped ........ 447
▫ Full Size Spare – If Equipped ............ 447
▫ Limited-Use Spare – If Equipped ......... 448
▫ Tire Spinning ....................... 448
▫ Tread Wear Indicators ................. 449
▫ Life Of Tire ........................ 450
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STARTING AND OPERATING 369

STARTING PROCEDURES
Before starting your vehicle, adjust your seat, adjust both
inside and outside mirrors, and fasten your seat belts.
WARNING!
•When leaving the vehicle, always remove the key
fob from the ignition and lock your vehicle.
•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.
Manual Transmission – If Equipped
Apply the parking brake, place the shift lever in NEU-
TRAL, and press the clutch pedal before starting the
vehicle. This vehicle is equipped with a clutch interlock-
ing ignition system. It will not start unless the clutch
pedal is pressed to the floor.
Four-Wheel Drive Models Only
In 4L mode, this vehicle will start regardless of whether
or not the clutch pedal is pressed to the floor. This feature
enhances off-road performance by allowing the vehicle to
start when in 4L without having to press the clutch pedal.
The “4WD Indicator Light” will illuminate when the
transfer case has been shifted into this mode.
Automatic Transmission – If Equipped
Start the vehicle with the shift lever in the PARK position
(vehicle can also be started in NEUTRAL). Apply the
brake before shifting to any driving range.
372 STARTING AND OPERATING

Shifting
Fully press the clutch pedal before shifting gears. As you
release the clutch pedal, lightly press the accelerator
pedal.
You should always use first gear when starting from a
standing position.
Recommended Vehicle Shift Speeds
To utilize your manual transmission efficiently for both
fuel economy and performance, it should be upshifted as
listed in recommended shift speed chart. Shift at the
vehicle speeds listed for acceleration. When heavily
loaded or pulling a trailer these recommended up-shift
speeds may not apply.
Manual Transmission Shift Speeds in MPH (KM/H)
En-
gine Speeds 1 to 2 2 to 3 3 to 4 4 to 5 5 to 6
3.6L Accel. 15 (24)24
(39) 34
(55) 47
(76) 56
(90)
Cruise 10 (16)19
(31) 27
(43) 37
(60) 41
(66)
NOTE: Vehicle speeds shown in the chart above are for
2H and 4H only, vehicle speeds in 4L would be signifi-
cantly less.
Shift Pattern
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STARTING AND OPERATING 377

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.
388 STARTING AND OPERATING

The transfer case is intended to be driven in the 2H
position for normal street and highway conditions such
as hard-surfaced roads.
In the event that additional traction is required, the
transfer case 4H and 4L positions can be used to lock the
front and rear driveshafts together, forcing the front andrear wheels to rotate at the same speed. This is accom-
plished by simply moving the shift lever to one of these
positions. The 4H and 4L positions are intended for loose,
slippery road surfaces only and not intended for normal
driving. Driving in the 4H and 4L positions on hard-
surfaced roads will cause increased tire wear and damage
to the driveline components.
The “4WD Indicator Light” (located in the instrument
cluster) alerts the driver that the vehicle is in four-wheel
drive, and the front and rear driveshafts are locked
together. The light will illuminate when the transfer case
is shifted into the 4H position.
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.
Four-Wheel Drive Shift Controls
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STARTING AND OPERATING 391

4H Position
This range locks the front and rear driveshafts together,
forcing the front and rear wheels to rotate at the same
speed. This range (4H) provides additional traction for
loose, slippery road surfaces and should not be used on
dry pavement.
The “4WD Indicator Light” (located in the instrument
cluster) will illuminate when the transfer case is shifted
into the 4H position.
N (Neutral) Position
This range disengages the front and rear driveshafts from
the powertrain. It is to be used for flat towing behind
another vehicle. Refer to “Recreational Towing” in “Start-
ing and Operating” for further information.
4L Position
This range locks the front and rear driveshafts together,
forcing the front and rear wheels to rotate at the samespeed. This range (4L) provides additional traction and
maximum pulling power for loose, slippery road surfaces
only. Do not exceed 25 mph (40 km/h).
The “4WD Indicator Light” (located in the instrument
cluster) will illuminate when the transfer case is shifted
into the 4L position.
NOTE:
When in 4WD, the “ESC Off Indicator Light”
will display in the instrument cluster.
Shifting Procedure
2H to 4H or 4H to 2H
Shifting between 2H and 4H can be made with the
vehicle stopped or in motion. With the vehicle in motion,
the transfer case will engage/disengage faster if you
momentarily release the accelerator pedal after complet-
ing the shift. Apply a constant force when shifting the
transfer case lever.
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STARTING AND OPERATING 393

4H to 4L or 4L to 4H
With the vehicle rolling at 2 to 3 mph (3 to 5 km/h), shift
an automatic transmission into NEUTRAL (N), or press
the clutch pedal on a manual transmission. While the
vehicle is coasting at 2 to 3 mph (3 to 5 km/h), shift the
transfer case lever firmly to the desired position. Do not
pause with the transfer case in N (Neutral). Once the shift
is completed, place the automatic transmission into
DRIVE or release the clutch pedal on a manual transmis-
sion.
NOTE:Shifting into or out of 4L is possible with the
vehicle completely stopped; however, difficulty may oc-
cur due to the mating teeth not being properly aligned.
Several attempts may be required for clutch teeth align-
ment and shift completion to occur. The preferred
method is with the vehicle rolling at 2 to 3 mph (3 to
5 km/h). Avoid attempting to engage or disengage 4L
with the vehicle moving faster than 2 to 3 mph (3 to
5 km/h).WARNING!
Failure to engage a position completely can cause
transfer case damage or loss of power and vehicle
control. You could have a collision. Do not drive the
vehicle unless the transfer case is fully engaged.
TRAC-LOK REAR AXLE — IF EQUIPPED
The Trac-Lok rear axle provides a constant driving force
to both rear wheels and reduces wheel spin caused by the
loss of traction at one driving wheel. If traction differs
between the two rear wheels, the differential automati-
cally proportions the usable torque by providing more
torque to the wheel that has traction.
Trac-Lok is especially helpful during slippery driving
conditions. With both rear wheels on a slippery surface, a
slight application of the accelerator will supply maxi-
mum traction.
394 STARTING AND OPERATING

To activate the system, press the bottom of the AXLE
LOCK switch once to lock the rear axle only (the “Rear
Axle Lock Indicator Light” will illuminate), press the
bottom of the switch again to lock the front axle (the
“Front Axle Lock Indicator Light” will illuminate). When
the rear axle is locked, pressing the switch again will lock
or unlock the front axle.
NOTE:The indicator lights will flash until the axles are
fully locked or unlocked.
To unlock the axles, press the top of the AXLE LOCK
switch.
Axle lock will disengage if the vehicle is taken out of 4L
(Low) range, or the ignition switch is turned to the OFF
position.ELECTRONIC SWAY BAR DISCONNECT — IF
EQUIPPED
Your vehicle may be equipped with an electronic discon-
necting stabilizer/sway bar. This system allows greater
front suspension travel in off-road situations.
This system is controlled by the SWAY BAR switch
located on the instrument panel (to the left of the steering
column).
396 STARTING AND OPERATING

Press the SWAY BAR switch to activate the system. Press
the switch again to deactivate the system. The “Sway Bar
Indicator Light” (located in the instrument cluster) will
illuminate when the bar is disconnected. The “Sway Bar
Indicator Light” will flash during activation transition, orwhen activation conditions are not met. The stabilizer/
sway bar should remain in on-road mode during normal
driving conditions.
WARNING!
Do not disconnect the stabilizer bar and drive on
hard-surfaced roads or at speeds above 18 mph
(29 km/h); you may lose control of the vehicle, which
could result in serious injury. The front stabilizer bar
enhances vehicle stability and is necessary for main-
taining control of the vehicle. The system monitors
vehicle speed and will attempt to reconnect the
stabilizer bar at speeds over 18 mph (29 km/h). This is
indicated by a flashing or solid “Sway Bar Indicator
Light.” Once vehicle speed is reduced below 14 mph
(22 km/h), the system will once again attempt to
return to off-road mode.
Sway Bar Switch
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STARTING AND OPERATING 397