2009 JEEP COMMANDER Engine

MAINTAINING YOUR VEHICLE
CONTENTS
Engine Compartment – 3.7L.............. 415
Engine Compartment – 4.7L.............. 416
Engine Compartment – 5.7L.............. 417
Onboard Diagnostic System — OBD II....... 418
▫Loose Fuel Filler Cap Message........... 418
Emissions Inspection And Maintenance
Programs............................ 419
Replacement Parts..................... 421
Dealer Service........................ 421Maintenance Procedures................. 422
▫Engine Oil......................... 422
▫Engine Air Cleaner Filter............... 424
▫Maintenance-Free Battery............... 425
▫Air Conditioner Maintenance............ 426
▫Body Lubrication..................... 427
▫Windshield Wiper Blades............... 428
▫Adding Washer Fluid.................. 428
▫Exhaust System...................... 429
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▫Cooling System...................... 431
▫Brake System....................... 437
▫Front/Rear Axle Fluid................. 438
▫Transfer Case....................... 439
▫Automatic Transmission................ 440
▫Maintenance After Off-Road Driving....... 443
▫Appearance Care And Protection From
Corrosion.......................... 444
Fuses.............................. 449
▫Interior Fuses....................... 449
▫Underhood Fuses (Power Distribution
Center)............................ 451
▫Underhood Fuses
(Integrated Power Module).............. 455Vehicle Storage....................... 456
Replacement Bulbs..................... 457
Bulb Replacement..................... 458
▫Head Light......................... 458
▫Front Turn Signal.................... 460
▫Front Fog Light...................... 461
▫Rear Tail, Stop, Turn Signal, And Backup
Lights............................. 462
▫Center High Mounted Stop Light (CHMSL) . . 464
Fluids And Capacities................... 465
Fluids, Lubricants, And Genuine Parts....... 466
▫Engine............................ 466
▫Chassis............................ 467
414 MAINTAINING YOUR VEHICLE

ENGINE COMPARTMENT – 3.7L
1 — Engine Coolant Reservoir 6 — Washer Fluid Reservoir
2 — Power Distribution Center 7 — Engine Oil Dipstick
3 — Brake Fluid Reservoir 8 — Engine Oil Fill
4 — Integrated Power Module 9 — Coolant Pressure Cap
5 — Battery 10 — Air Cleaner FilterMAINTAINING YOUR VEHICLE 4157

ENGINE COMPARTMENT – 4.7L
1 — Engine Coolant Reservoir 7 — Battery
2 — Automatic Transmission Dipstick 8 — Washer Fluid Reservoir
3 — Engine Oil Dipstick 9 — Engine Oil Fill
4 — Power Distribution Center 10 — Coolant Pressure Cap
5 — Brake Fluid Reservoir 11 — Air Cleaner Filter
6 — Integrated Power Module 416 MAINTAINING YOUR VEHICLE

ENGINE COMPARTMENT – 5.7L
1 — Engine Coolant Reservoir 7 — Washer Fluid Reservoir
2 — Automatic Transmission Dipstick 8 — Engine Oil Dipstick
3 — Power Distribution Center 9 — Engine Oil Fill
4 — Brake Fluid Reservoir 10 — Coolant Pressure Cap
5 — Integrated Power Module 11 — Air Cleaner Filter
6 — BatteryMAINTAINING YOUR VEHICLE 4177

ONBOARD DIAGNOSTIC SYSTEM — OBD II
Your vehicle is equipped with a sophisticated onboard
diagnostic system called OBD II. This system monitors
the performance of the emissions, engine, and automatic
transmission control systems. When these systems are
operating properly, your vehicle will provide excellent
performance and fuel economy, as well as engine emis-
sions well within current government regulations.
If any of these systems require service, the OBD II system
will turn on the “Malfunction Indicator Light.” It will
also store diagnostic codes and other information to
assist your service technician in making repairs. Al-
though your vehicle will usually be drivable and not
need towing, see your authorized dealer for service as
soon as possible.CAUTION!
•Prolonged driving with the “Malfunction Indica-
tor Light” on could cause further damage to the
emission control system. It could also affect fuel
economy and drivability. The vehicle must be
serviced before any emissions tests can be per-
formed.
•If the “Malfunction Indicator Light” is flashing
while the engine is running, severe catalytic con-
verter damage and power loss will soon occur.
Immediate service is required.
Loose Fuel Filler Cap Message
After fuel is added, the vehicle diagnostic system can
determine if the fuel filler cap is loose, improperly
installed, or damaged. A “CHECK GASCAP” message
will be displayed in the EVIC (Refer to Section 4 of this
418 MAINTAINING YOUR VEHICLE

manual). Tighten the gas cap until aclickingsound is
heard. This is an indication that the gas cap is properly
tightened.
The message will remain displayed until the vehicle
diagnostic system can retest the fuel system. The test will
perform the next time the vehicle is started, if the vehicle
was keyed off above 40°F (4°C) outside temperature and
the following vehicle start is above 40°F (4°C) outside
temperature. It may be possible to have a message that
will not clear due to the test being disabled due to low
outside temperatures. If the test is performed and the
problem is gone, the message will disappear.
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. See
your authorized dealer for service.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 that require an Inspection and Mainte-
nance (I/M), this check verifies the Malfunction
Indicator Light (MIL) is functioning and is not on
when the engine is running, and that the OBD II system
is ready for testing.
Normally, the OBD II system will be ready. The OBD II
system maynotbe ready if your vehicle was recently
serviced, recently had a dead battery or a battery replace-
ment. If the OBD II system should be determined not
ready for the I/M test, your vehicle may fail the test.
MAINTAINING YOUR VEHICLE 419
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Your vehicle has a simple ignition key-actuated test,
which you can use prior to going to the test station. To
check if your vehicle’s OBD II system is ready, you must
do the following:
1. Insert your ignition key into the ignition switch.
2. Turn the ignition to the ON position, but do not crank
or start the engine.
3. If you crank or start the engine, you will have to start
this test over.
4. As soon as you turn your key to the ON position, you
will see the MIL symbol come on as part of a normal bulb
check.
5. Approximately 15 seconds later, one of two things will
happen:
a. The MIL will flash for about 10 seconds and then
return to being fully illuminated until you turn OFFthe ignition or start the engine. This means that your
vehicle’s OBD II system isnot readyand you should
notproceed to the I/M station.
b. The MIL will not flash at all and will remain fully
illuminated until you turn OFF the ignition or start the
engine. This means that your vehicle’s OBD II system
isreadyand you can proceed to the I/M station.
If your OBD II system isnot ready,you should see your
authorized dealer or repair facility. If your vehicle was
recently serviced or had a battery failure or replacement,
you may need to do nothing more than drive your
vehicle as you normally would in order for your OBD II
system to update. A recheck with the above test routine
may then indicate that the system is now ready.
420 MAINTAINING YOUR VEHICLE