2012 JEEP WRANGLER check engine light

SENTRY KEY
The Sentry KeyImmobilizer System prevents unauthor-
ized vehicle operation by disabling the engine. The
system does not need to be armed or activated. Operation
is automatic, regardless of whether the vehicle is locked
or unlocked.
The system uses ignition keys that have an embedded
electronic chip (transponder) to prevent unauthorized
vehicle operation. Therefore, only keys that are pro-
grammed to the vehicle can be used to start and operate
the vehicle. The system will shut the engine off in two
seconds if someone uses an invalid key to try to start the
engine.
NOTE: A key that has not been programmed is also
considered an invalid key, even if it is cut to fit the
ignition switch lock cylinder for that vehicle.
During normal operation, after turning on the ignition
switch, the Vehicle Security Light will turn on for three seconds for a bulb check. If the light remains on after the
bulb check, it indicates that there is a problem with the
electronics. In addition, if the Vehicle Security Light
begins to flash after the bulb check, it indicates that
someone used an invalid key to try to start the engine.
Either of these conditions will result in the engine being
shut off after two seconds.
If the Vehicle Security Light turns on during normal
vehicle operation (vehicle running for longer than 10 sec-
onds), it indicates that there is a fault in the electronics.
Should this occur, have the vehicle serviced as soon as
possible by an authorized dealer.
CAUTION!
The Sentry Key
Immobilizer system is not compat-
ible with some after-market remote starting systems.
Use of these systems may result in vehicle starting
problems and loss of security protection.
16 THINGS TO KNOW BEFORE STARTING YOUR VEHICLE

Periodic Safety Checks You Should Make Outside
The Vehicle
Tires
Examine tires for excessive tread wear and uneven wear
patterns. Check for stones, nails, glass, or other objects
lodged in the tread or sidewall. Inspect the tread for cuts
and cracks. Inspect sidewalls for cuts, cracks and bulges.
Check the wheel nuts for tightness. Check the tires
(including spare) for proper cold inflation pressure.
Lights
Have someone observe the operation of exterior lights
while you work the controls. Check turn signal and high
beam indicator lights on the instrument panel.
Door Latches
Check for positive closing, latching, and locking.
Fluid Leaks
Check area under vehicle after overnight parking for fuel,
engine coolant, oil, or other fluid leaks. Also, if gasoline
fumes are detected or if fuel, power steering fluid, or
brake fluid leaks are suspected, the cause should be
located and corrected immediately.2
THINGS TO KNOW BEFORE STARTING YOUR VEHICLE 89

NOTE:The engine must be running before the head-
lights will turn on in the Automatic mode.
Turn Signals
Move the multifunction lever up or down and the arrows
on each side of the instrument cluster flash to show
proper operation of the front and rear turn signal lights. NOTE:
•If either light remains on and does not flash, or there is
a very fast flash rate, check for a defective outside light
bulb. If an indicator fails to light when the lever is
moved, it would suggest that the indicator bulb is
defective.
Headlight SwitchTurn Signal Operation
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UNDERSTANDING THE FEATURES OF YOUR VEHICLE 151

INSTRUMENT CLUSTER DESCRIPTIONS
1. Fuel Gauge
The pointer shows the level of fuel in the fuel tank when
the ignition switch is in the ON/RUN position.
2. Charging System LightThis light shows the status of the electrical charg-
ing system. The light should come on when the
ignition switch is first turned to ON/RUN, and remain
on briefly as a bulb check. If the light stays on or comes
on while driving, turn off some of the vehicle’s non-
essential electrical devices or increase engine speed (if at
idle). If the charging system light remains on, it means
that the vehicle is experiencing a problem with the
charging system. Obtain SERVICE IMMEDIATELY. See
an authorized dealer.
If jump starting is required, refer to “Jump Starting
Procedures” in “What To Do In Emergencies”. 3. Front Fog Light Indicator — If Equipped
This indicator will illuminate when the front fog
lights are on.
4. Low Fuel Warning Light When the fuel level reaches approximately 2.8 gal
(10.6L) this light will turn on and a single chime
will sound.
5. Speedometer
Indicates vehicle speed.
6. Front Axle Lock Indicator — If Equipped Indicates when the front axle lock has been
activated.
7. Seat Belt Reminder Light When the ignition switch is first turned to ON/
RUN, this light will turn on for four to eight
seconds as a bulb check. During the bulb check, if
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UNDERSTANDING YOUR INSTRUMENT PANEL 269

the driver’s seat belt is unbuckled, a chime will sound.
After the bulb check or when driving, if the driver seat
belt remains unbuckled, the Seat Belt Reminder Light
will flash or remain on continuously. Refer to “Occupant
Restraints” in “Things To Know Before Starting Your
Vehicle” for further information.
8. Turn Signal IndicatorsThe left or right arrow will flash with the corre-
sponding exterior turn signal lights when the turn
signal lever is operated. A chime will sound if the vehicle
is driven more than 1 mile (1.6 km) with either turn signal
on.
NOTE: If either indicator flashes at a rapid rate, check
for a defective outside light bulb.
9. Oil Pressure Warning Light This light indicates low engine oil pressure. The
light should turn on momentarily when the engine
is started; if the bulb does not come on, have the system checked by an authorized dealer. If the light turns on
while driving, stop the vehicle and shut off the engine as
soon as possible. A chime will sound when this light
turns on.
Do not operate the vehicle until the cause is corrected.
This light does not indicate how much oil is in the engine.
The engine oil level must be checked under the hood.
10. High Beam Indicator
This indicator shows that the high beam head-
lights are on. Push the multifunction control lever
away from you to switch the headlights to high beam.
Pull the lever toward you to switch the headlights back to
low beam. If the driver’s door is open, and the headlights
or park lights are left on, the high beam indicator light
will remain illuminated and a chime will sound.
270 UNDERSTANDING YOUR INSTRUMENT PANEL

13. Air Bag Warning LightThis light will turn on for four to eight seconds
as a bulb check when the ignition switch is first
turned to ON/RUN. If the light is either not on
during starting, stays on, or turns on while
driving, have the system inspected at an authorized
dealer as soon as possible. Refer to “Occupant Restraints”
in “Things To Know Before Starting Your Vehicle” for
further information.
14. Rear Axle Lock Indicator — If Equipped This light indicates when the rear axle lock has
been activated.
15. Tachometer
Indicates the engine speed in revolutions per minute
(RPM x 1000).CAUTION!
Do not operate the engine with the tachometer
pointer in the red area. Engine damage will occur.
16. Coolant Temperature Warning Light This light warns of an overheated engine condi-
tion. If the light turns on while driving, safely pull
over and stop the vehicle. If the A/C system is on,
turn it off. Also, shift the transmission into NEUTRAL
and idle the vehicle. If the temperature reading does not
return to normal, turn the engine off immediately and
call for service.
NOTE: As the coolant temperature gauge approaches
H, this indicator will illuminate and a single chime will
sound. Further overheating will cause the temperature
gauge to pass H.In this case, the indicator light will
flash continuously and a continuous chime will sound,
until the engine is allowed to cool.
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UNDERSTANDING YOUR INSTRUMENT PANEL 273

WARNING!
A hot engine cooling system is dangerous. You or
others could be badly burned by steam or boiling
coolant. You may want to call an authorized dealer-
ship for service if your vehicle overheats. If you
decide to look under the hood yourself, see “Main-
taining Your Vehicle”. Follow the warnings under the
Cooling System Pressure Cap paragraph.
19. Cruise Indicator This indicator shows when the electronic speed
control system is turned on.
20. 4WD Indicator Light — If Equipped This light alerts the driver that the vehicle is in
the four-wheel drive mode, and the front and
rear driveshafts are mechanically locked to-
gether forcing the front and rear wheels to
rotate at the same speed. 21. Odometer / Trip Odometer / ECO
(Fuel Saver Indicator) Button
Press this button to change the display from odometer to
either of the two trip odometer settings or the “ECO”
display. Trip A or Trip B will appear when in the trip
odometer mode. Press and hold the button for two
seconds to reset the trip odometer to 0 miles or kilome-
ters. The odometer must be in trip mode to reset.
22. Shift Lever Indicator
The Shift Lever Indicator is self-contained within the
instrument cluster. It displays the gear position of the
automatic transmission.
23. Tire Pressure Monitoring Telltale Light
Each tire, including the spare (if provided),
should be checked monthly when cold and
inflated to the inflation pressure recommended
by the vehicle manufacturer on the vehicle
placard or tire inflation pressure label. (If your vehicle has
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UNDERSTANDING YOUR INSTRUMENT PANEL 275

means the engine oil change interval may fluctuate
dependent upon your personal driving style.
Unless reset, this message will continue to display each
time you turn the ignition switch to the ON/RUN
position. To turn off the message temporarily, press and
release the Trip Odometer button on the instrument
cluster. To reset the oil change indicator system (after
performing the scheduled maintenance), refer to the
following procedure:1. Turn the ignition switch to the ON/RUN position
(do not start the engine).
2. Fully depress the accelerator pedal slowly three
times within 10 seconds.
3. Turn the ignition switch to the OFF/LOCK position.
NOTE: If the indicator message illuminates when you
start the vehicle, the oil change indicator system did not
reset. If necessary, repeat this procedure. 25. Malfunction Indicator Light (MIL)
The Malfunction Indicator Light (MIL) is a part of
an Onboard Diagnostic System called OBD II that
monitors engine and automatic transmission con-
trol systems. The light will illuminate when the ignition
is in the ON position before engine start. If the bulb does
not come on when turning the key from OFF to ON/
RUN, have the condition checked promptly.
Certain conditions, such as a loose or missing gas cap,
poor quality fuel, etc., may illuminate the light after
engine start. The vehicle should be serviced if the light
stays on through several typical driving styles. In most
situations, the vehicle will drive normally and will not
require towing.
When the engine is running, the MIL may flash to alert
serious conditions that could lead to immediate loss of
power or severe catalytic converter damage. The vehicle
should be serviced as soon as possible if this occurs.
280 UNDERSTANDING YOUR INSTRUMENT PANEL