2010 JEEP COMMANDER fuel cap

5. Malfunction Indicator Light (MIL)The Malfunction Indicator Light (MIL) is part of
an onboard diagnostic system called OBD II that
monitors engine and automatic transmission con-
trol systems. The light will illuminate when the key 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 fuel quality, etc., may illuminate the light after
engine start. The vehicle should be serviced if the light
stays on through several of your typical driving cycles. In
most situations, the vehicle will drive normally and will
not require towing.CAUTION!
Prolonged driving with the MIL on could cause
damage to the engine control system. It also could
affect fuel economy and drivability. If the MIL is
flashing, severe catalytic converter damage and
power loss will soon occur. Immediate service is
required.
WARNING!
A malfunctioning catalytic converter, as referenced
above, can reach higher temperatures than in normal
operating conditions. This can cause a fire if you
drive slowly or park over flammable substances such
as dry plants or wood or cardboard, etc. This could
result in death or serious injury to the driver, occu-
pants or others.
162 UNDERSTANDING YOUR INSTRUMENT PANEL

▫3.7 Engine ......................... 314
▫ 5.7L Engine ........................ 314
▫ Reformulated Gasoline ................ 315
▫ Gasoline/Oxygenate Blends ............. 315
▫ E-85 Usage In Non-Flex Fuel Vehicles ...... 315
▫ MMT In Gasoline .................... 316
▫ Materials Added To Fuel ............... 316
▫ Fuel System Cautions ................. 317
▫ Carbon Monoxide Warnings ............ 317
 Adding Fuel ......................... 318
▫ Fuel Filler Cap (Gas Cap) .............. 318
 Vehicle Loading ...................... 320
▫ Certification Label ................... 320 
Trailer Towing ........................ 323
▫ Common Towing Definitions ............ 323
▫ Trailer Hitch Classification .............. 327
▫ Trailer Towing Weights (Maximum Trailer
Weight Ratings) ..................... 328
▫ Trailer And Tongue Weight ............. 329
▫ Towing Requirements ................. 330
▫ Towing Tips ........................ 335
 Snow Plow .......................... 336
 Recreational Towing (Behind Motorhome, Etc.) . 336
▫ Towing – Two-Wheel Drive Models ....... 336
▫ Towing — Quadra-Trac I (Single-Speed
Transfer Case) Four-Wheel Drive Models . . . 337
▫ Towing — Quadra–Trac II /Quadra–Drive
II Four-Wheel Drive Models ............. 337
242 STARTING AND OPERATING

CAUTION!
•The TPMS has been optimized for the original
equipment tires and wheels. TPMS pressures have
been established for the tire size equipped on your
vehicle. Undesirable system operation or sensor
damage may result when using replacement
equipment that is not of the same size, type, and/or
style. Aftermarket wheels can cause sensor dam-
age. Do not use aftermarket tire sealants or balance
beads if your vehicle is equipped with a TPMS, as
damage to the sensors may result.
•After inspecting or adjusting the tire pressure
always reinstall the valve stem cap. This will
prevent moisture and dirt from entering the valve
stem, which could damage the Tire Pressure Moni-
toring Sensor.NOTE:
•The TPMS is not intended to replace normal tire care
and maintenance, or to provide warning of a tire
failure or condition.
•The TPMS should not be used as a tire pressure gauge
while adjusting your tire pressure.
•Driving on a significantly under-inflated tire causes
the tire to overheat and can lead to tire failure.
Under-inflation also reduces fuel efficiency and tire
tread life, and may affect the vehicle’s handling and
stopping ability.
•The TPMS is not a substitute for proper tire mainte-
nance, and it is the driver ’s responsibility to maintain
correct tire pressure using an accurate tire gauge, even
if under-inflation has not reached the level to trigger
illumination of the Tire Pressure Monitoring Telltale
Light.
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STARTING AND OPERATING 305

•Do not inhale exhaust gases. They contain carbon
monoxide, a colorless and odorless gas which can kill.
Never run the engine in a closed area, such as a
garage, and never sit in a parked vehicle with the
engine running for an extended period. If the vehicle is
stopped in an open area with the engine running for
more than a short period, adjust the ventilation system
to force fresh, outside air into the vehicle.
•Guard against carbon monoxide with proper mainte-
nance. Have the exhaust system inspected every time
the vehicle is raised. Have any abnormal conditions
repaired promptly. Until repaired, drive with all side
windows fully open.
•Keep the liftgate closed when driving your vehicle to
prevent carbon monoxide and other poisonous ex-
haust gases from entering the vehicle.
ADDING FUEL
Fuel Filler Cap (Gas Cap)
The gas cap is located behind the fuel filler door, on the
driver’s side of the vehicle. If the gas cap is lost or
damaged, be sure the replacement cap is for use with this
vehicle.
Fuel Filler Cap
318 STARTING AND OPERATING

CAUTION!
•Damage to the fuel system or emission control
system could result from using an improper fuel
cap (gas cap). A poorly fitting cap could let impu-
rities into the fuel system. Also, a poorly fitting
aftermarket cap can cause the “Malfunction Indi-
cator Light” (MIL) to illuminate, due to fuel vapors
escaping from the system.
•A poorly fitting gas cap may cause the MIL to turn
on.
•To avoid fuel spillage and overfilling, do not “top
off” the fuel tank after filling.
NOTE: When the fuel nozzle “clicks” or shuts off, the
fuel tank is full.
WARNING!
•Never have any smoking materials lit in or near
the vehicle when the gas cap is removed or the
tank filled.
•Never add fuel when the engine is running. This is
in violation of most state and federal fire regula-
tions and will cause the MIL to turn on.
NOTE: Tighten the gas cap about one–quarter turn until
you hear one click. This is an indication that cap is
properly tightened.
If the gas cap is not tighten properly, the MIL will come
on. Be sure the gas cap is tightened every time the vehicle
is refueled.
5
STARTING AND OPERATING 319

Loose Fuel Filler Cap Message
If the vehicle diagnostic system determines that the fuel
filler cap is loose, improperly installed, or damaged, a
“CHECK GASCAP” message will be displayed in the
EVIC (Electronic Vehicle Information Center). Refer to
“Electronic Vehicle Information Center” in Section 4 of
this manual. Tighten the fuel filler cap until a “clicking”
sound is heard. This is an indication that the fuel filler
cap is properly tightened. Refer to “Onboard Diagnostic
System — OBDII” in Section 7 of this manual for more
information.
WARNING!
A fire may result if gasoline is pumped into a
portable container that is inside of a vehicle. You
could be burned. Always place gas containers on the
ground while filling.
CAUTION!
Damage to the fuel system or emission control sys-
tem could result from using an improper fuel tank
filler cap (gas cap). A poorly fitting cap could let
impurities into the fuel system.
WARNING!
•Never add fuel when the engine is running.
•Never have any smoking materials lit in or near
the vehicle when the fuel cap is removed or the
tank filled.
VEHICLE LOADING
Certification Label
As required by National Highway Traffic Safety Admin-
istration regulations, your vehicle has a certification label
affixed to the driver’s side door or B-Pillar.
320 STARTING AND OPERATING

Inflation Pressure
This is the cold tire inflation pressure for your vehicle for
all loading conditions up to full GAWR.
Curb Weight
The curb weight of a vehicle is defined as the total weight
of the vehicle with all fluids, including vehicle fuel, at full
capacity conditions, and with no occupants or cargo
loaded into the vehicle. The front and rear curb weight
values are determined by weighing your vehicle on a
commercial scale before any occupants or cargo are
added.
Loading
The actual total weight and the weight of the front and
rear of your vehicle at the ground can best be determined
by weighing it when it is loaded and ready for operation.
The entire vehicle should first be weighed on a commer-
cial scale to ensure that the GVWR has not been ex-
ceeded. The weight on the front and rear of the vehicleshould then be determined separately to be sure that the
load is properly distributed over front and rear axle.
Weighing the vehicle may show that the GAWR of either
the front or rear axles has been exceeded, but the total
load is within the specified GVWR. If so, weight must be
shifted from front to rear, or rear to front, as appropriate
until the specified weight limitations are met. Store the
heavier items down low and be sure that the weight is
distributed equally. Stow all loose items securely before
driving.
Improper weight distributions can have an adverse affect
on the way your vehicle steers and handles, and the way
the brakes operate.
322 STARTING AND OPERATING

MAINTAINING YOUR VEHICLE
CONTENTS
Engine Compartment – 3.7L .............. 357
 Engine Compartment – 5.7L .............. 358
 Onboard Diagnostic System – OBD II ....... 359
▫ Loose Fuel Filler Cap Message ........... 359
 Emissions Inspection And Maintenance
Programs ............................ 360
 Replacement Parts ..................... 362
 Dealer Service ........................ 362
 Maintenance Procedures ................. 362 ▫
Engine Oil ......................... 363
▫ Engine Oil Filter ..................... 366
▫ Engine Air Cleaner Filter ............... 366
▫ Maintenance-Free Battery .............. 367
▫ Air Conditioner Maintenance ............ 368
▫ Body Lubrication .................... 369
▫ Windshield Wiper Blades ............... 369
▫ Adding Washer Fluid ................. 370
▫ Exhaust System ..................... 371
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