check engine light JEEP WRANGLER 2007 JK / 3.G Owners Manual

To Release the Steering Wheel Lock
Insert the key in the ignition and turn the wheel slightly
to the right or left to disengage the lock.
NOTE:If you turned the wheel to the right to engage
the lock, you must turn the wheel slightly to the right to
disengage it. If you turned the wheel to the left to engage
the lock, turn the wheel slightly to the left to disengage it.
SENTRY KEY IMMOBILIZER SYSTEM
The Sentry Key Immobilizer System (SKIM) prevents
unauthorized operation of the vehicle by disabling the
engine. The system will shut the engine down after 2
seconds of running if an invalid key is used to start the
vehicle. This system utilizes ignition keys which have an
electronic chip (transponder) embedded into them. Only
keys that have been programmed to the vehicle can be
used to start and operate the vehicle for longer than the
2 second validation time period.The Sentry Key Immobilizer System does not need to be
armed or activated. Operation of the system is automatic
regardless of whether or not the vehicle is locked or
unlocked. During normal operation, the “Security Alarm
System Indicator Light” will come on for 3 seconds
immediately after the ignition switch is turned on for a
bulb check. Afterwards, if the bulb remains on, this
indicates a malfunction in the electronics. If the bulb
begins to flash immediately after the ignition switch is
turned on, this indicates that an invalid key is being used
to start the vehicle. Both of these conditions will result in
the engine being shut down after 2 seconds of running.
Keep in mind that a key which has not been programmed
is also considered an invalid key even if it is cut to fit the
ignition for that vehicle.
If the “Security Alarm System Indicator Light” comes on
during normal vehicle operation (it has been running for
16 THINGS TO KNOW BEFORE STARTING YOUR VEHICLE

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.
NOTE:A tone will chime if the turn signals are left on
for more than 1 mile (2 km).
Daytime Running Lights — If Equipped
The headlights come on at a low intensity level after the
vehicle has been driven approximately 3 feet (1 meter).
They will turn off when the vehicle is turned off or when
the headlights are switched on.
WINDSHIELD WIPERS AND WASHERS
CAUTION!
In cold weather, always turn off the wiper switch and
allow the wipers to return to the park position before
turning off the engine. If the wiper switch is left on
and the wipers freeze to the windshield, damage to
the wiper motor may occur when the vehicle is
restarted.
Intermittent Wiper System
Use the intermittent wiper when weather conditions
make a single wiping cycle, with a variable pause be-
tween cycles, desirable. Move the lever to the DELAY
position, then select the delay interval by turning the end
of the lever. The delay can be regulated from a maximum
of approximately 18 seconds between cycles, to a cycle
every second.
UNDERSTANDING THE FEATURES OF YOUR VEHICLE 101
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6. Front Axle Lock Indicator Light — If Equipped
Indicates when the front axle lock has been
activated.
7. Seat Belt Indicator Light
A warning chime and an indicator light will alert
you to buckle the seat belts. When the belt is
buckled, the chime will stop, but the light will stay
on until it times out (about 6 seconds).
8. Turn Signal Indicator Lights
The arrows will flash with the exterior turn signals
when the turn signal lever is operated. A tone will
chime if the turn signals are left on for more than 1 mile
(2 km).
9. Oil Pressure Warning Light
Shows low engine oil pressure. The light will come
on and remain on when the ignition switch isturned from the OFF to the ON position, and the light
will turn off after the engine is started. If the bulb does
not come on, have the system checked by your autho-
rized dealer.
If the warning light comes on and remains on while
driving, stop the vehicle and shut off the engine. DO
NOT OPERATE THE VEHICLE UNTIL THE CAUSE IS
CORRECTED. Also, a single chime will sound.
10. High Beam Indicator Light
This light shows that the headlights are on high
beam. Pull the turn signal lever towards the
steering wheel to switch the headlights from high or low.
If the driver’s door is open, and the headlights or
parklights are left on, the “High Beam Indicator Light”
will flash and a chime will sound.
UNDERSTANDING YOUR INSTRUMENT PANEL 203
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24. Odometer/Trip Odometer
The odometer shows the total distance the vehicle has
been driven.
U.S. federal regulations require that upon transfer of
vehicle ownership, the seller certify to the purchaser the
correct mileage that the vehicle has been driven. There-
fore, if the odometer reading is changed during repair or
replacement, be sure to keep a record of the reading
before and after the service so the correct mileage can be
determined.
25. Malfunction Indicator Light
This light is a part of an Onboard Diagnostic
System called OBD II that monitors engine, and
automatic transmission control 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, 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 “Malfunction Indicator
Light” 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.
26. Electronic Stability Program (ESP) Indicator
Light/Traction Control System (TCS) Indicator Light
This indicator light starts to flash as soon as the
tires lose traction and the ESP system becomes
active. The “ESP/TCS Indicator Light” also
flashes when TCS is active. If the “ESP/TCS
Indicator Light” begins to flash during acceleration, ease
208 UNDERSTANDING YOUR INSTRUMENT PANEL

up on the accelerator and apply as little throttle as
possible. Be sure to adapt your speed and driving to the
prevailing road conditions. The “ESP/TCS Indicator
Light” will flash any time the ESP or TCS is active and
helping to improve vehicle stability. If the “ESP/TCS
Indicator Light” is on solid, the ESP system has been
turned off by the driver or a temporary condition exists
that will not allow full ESP function.
27. O/D (Overdrive) Off Indicator Light
This light will illuminate when the O/D OFF
button has been selected. The O/D OFF button is
located on the gear shift lever.
28. Sway Bar Indicator Light — If Equipped
This light will illuminate when the front sway
bar is disconnected.29. Electronic Stability Program (ESP) Warning
Light/Brake Assist System (BAS) Warning Light
The ESP/BAS warning light in the instrument
cluster comes on when the ignition switch is
turned to the “ON” position. The light should
go out with the engine running. If the ESP/
BAS warning light comes on continuously with the
engine running, a malfunction has been detected in either
the ESP or the BAS system. If this light stays illuminated,
have the ESP and BAS checked at your authorized dealer
as soon as possible. Refer to “Electronic Brake Control
System” in Section 5 for more information.
UNDERSTANDING YOUR INSTRUMENT PANEL 209
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30. Electronic Throttle Control (ETC) Warning Light —
If Equipped
This light informs you of a problem with the
Electronic Throttle Control System. If a prob-
lem is detected while the engine is running, the
light will either stay on or flash depending on
the nature of the problem. Cycle the ignition key when
the vehicle is safely and completely stopped and the gear
selector is placed in the P (Park) position. The light
should turn off. If the light remains on with the engine
running, your vehicle will usually be drivable, however,
see your dealer for service as soon as possible.
If the light continues to flash when the engine is running,
immediate service is required and you may experience
reduced performance, an elevated / rough idle, or engine
stall and your vehicle may require towing. The light will
come on when the ignition is first turned on and remainon briefly as a bulb check. If the light does not come on
during starting, have the system checked by an autho-
rized dealer.
31. Compass/Mini-Trip Computer Display — If
Equipped
When the appropriate conditions exist, this display
shows the Mini-Trip Computer messages. Refer to “Mini-
Trip Computer” later in this section.
32. Compass/Mini-Trip Computer Button—If Equipped
Press this button to switch between the different func-
tions.
210 UNDERSTANDING YOUR INSTRUMENT PANEL

The automatic transmission fluid and filter should be
changed if you REGULARLY tow a trailer for more than
45 minutes of continuous operation. See “Schedule B” in
section 8 of this manual for transmission fluid change
intervals.
NOTE:Check the automatic transmission fluid level
before towing.
Towing Tips — O/D Off (If Equipped)
To reduce potential for automatic transmission overheat-
ing, turn the “O/D OFF” feature OFF when driving in
hilly areas or shift the transmission to Drive position 2 on
more severe grades. Refer to “Transmission Shifting” in
this section.
Towing Tips — Electronic Speed Control (If
Equipped)

Don’t use in hilly terrain or with heavy loads.
When using the speed control, if you experience speed
drops greater than 10 mph (16 km/h), disengage until
you can get back to cruising speed.
Use speed control in flat terrain and with light loads to
maximize fuel efficiency.
Towing Tips — Cooling System
To reduce potential for engine and transmission over-
heating, take the following actions:
Highway Driving
Reduce speed.
Air Conditioning
Turn off temporarily.
refer to Cooling System Operating information in the
Maintenance section of this manual for more informa-
tion.
STARTING AND OPERATING 345
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Loose Fuel Filler Cap Message
After fuel is added, the vehicle diagnostic system can
determine if the fuel filler cap is possibly loose, improp-
erly installed, or damaged. A loose fuel filler cap message
will be displayed in the instrument cluster. Tighten the
gas cap until aclickingsound is heard. This is an
indication that the gas cap is properly tightened. Press
the odometer reset button to turn the message off. If the
problem persists, the message will appear the next time
the vehicle is started. This might indicate a damaged cap.
If the problem is detected twice in a row, the system will
turn on the Malfunction Indicator Light (MIL). Resolving
the problem will turn the MIL light off.
EMISSIONS INSPECTION AND MAINTENANCE
PROGRAMS
In some localities, it may be a legal requirement to pass
an inspection of your vehicle’s emissions control system.
Failure to pass could prevent vehicle registration.
For states, which have an I/M (Inspection and
Maintenance) requirement, this check verifies the
following: the MIL (Malfunction Indicator Light)
is functioning and is not on when the engine is running,
and that the OBD (On Board Diagnostic) system is ready
for testing.
Normally, the OBD system will be ready. The OBD
system maynotbe ready if your vehicle was recently
serviced, if you recently had a dead battery, or a battery
replacement. If the OBD system should be determined
not ready for the I/M test, your vehicle may fail the test.
366 MAINTAINING YOUR VEHICLE

WARNING!
Worn brake hoses can burst and cause brake failure.
You could have an accident. If you see any signs of
cracking, scuffing, or worn spots, have the brake
hoses replaced immediately.
Brake Master Cylinder
The fluid level in the master cylinder should be checked
when performing under hood services, or immediately if
the BRAKE warning light shows system failure
Be sure to clean the top of the master cylinder area before
removing the cap. If necessary, add fluid to bring the
fluid level up to the requirements described on the brake
fluid reservoir. With disc brakes, fluid level can be
expected to fall as the brake pads wear. Brake fluid levelshould be checked when pads are replaced. However,
low fluid level may be caused by a leak and a checkup
may be needed.
Use only manufacturer’s recommended brake fluid, refer
to Fluids, Lubricants, and Genuine Parts for correct fluid
type.
WARNING!
•Use of a brake fluid that may have a lower initial
boiling point or unidentified as to specification,
may result in sudden brake failure during hard
prolonged braking. You could have an accident.
•Overfilling the brake fluid reservoir can result in
spilling brake fluid on hot engine parts and the
brake fluid catching fire.
MAINTAINING YOUR VEHICLE 387
7

At Each Stop for Fuel
•Check the engine oil level about 5 minutes after a fully
warmed engine is shut off. Checking the oil level while
the vehicle is on level ground will improve the accu-
racy of the oil level reading. Add oil only when the
level is at or below the ADD or MIN mark.
•Check the windshield washer solvent, add as required.
Once a Month
•Check the tire pressure and look for unusual wear or
damage.
•Inspect the battery and clean and tighten the terminals
as required.
•Check the fluid levels of the coolant reservoir, brake
master cylinder, and transmission, and add as needed.
•Check all lights and all other electrical items for correct
operation.
At Each Oil Change
•Change the engine oil filter.
•Inspect the exhaust system.
•Inspect brake hoses.
•Inspect the CV joints (If equipped) and front suspen-
sion components.
•Check the coolant level, hoses, and clamps.
•After completion of off-road operation, the underside
of the vehicle should be thoroughly inspected. Exam-
ine threaded fasteners for looseness.
418 MAINTENANCE SCHEDULES
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