check engine JEEP COMMANDER 2006 1.G User Guide

N (Neutral)
Neutral — Disengages both the front and rear driveshafts
from the powertrain. To be used for flat towing behind
another vehicle. Refer to “Recreational Towing” in Sec-
tion 5 of this manual.
4 LOW
Four Wheel Drive Low Range — Low speed 4 wheel
drive. Locks the front and rear driveshafts together.
Forces the front and rear wheels to rotate at the same
speed. Additional traction and maximum pulling power
for loose, slippery road surfaces only. Do not exceed 25
mph (40 km/h).
Shifting Procedures
4HIto4LOW
With the vehicle at speeds of 0 to 3 mph (0 to 5 km/h),
key ON or engine running, shift the transmission into N
(Neutral), and raise the transfer case T-handle. “The 4WD
LOW Indicator Lamp” in the instrument cluster will
begin to flash and remain on solid when the shift is
complete. Release the T-handle.
NOTE:If shift conditions/interlocks are not met, or a
transfer case motor temperature protection condition
exists, a “CHECK SHIFT PROCEDURES” message will
flash from the EVIC (Electronic Vehicle Information Cen-
ter). Refer to “Electronic Vehicle Information Center
(EVIC)” in Section 4 of this manual. (See page 186 for
more information.)
266 STARTING AND OPERATING

4LOWto4HI
With the vehicle at speeds of 0 to 3 mph (0 to 5 km/h),
key ON or engine running, shift the transmission into N
(Neutral), and raise the transfer case T-handle. The “4WDLOW Indicator Lamp” in the instrument cluster will flash
and go out when the shift is complete. Release the
T-handle.
NOTE:If shift conditions/interlocks are not met, or a
transfer case motor temperature protection condition
exists, a “CHECK SHIFT PROCEDURES” message will
flash from the EVIC (Electronic Vehicle Information Cen-
ter). Refer to “Electronic Vehicle Information Center
(EVIC)” in Section 4 of this manual. (See page 186 for
more information.)
NOTE:Shifting into or out of 4WD LOW is possible
with the vehicle completely stopped, however difficulty
may occur due to the mating clutch teeth not being
properly aligned. Several attempts may be required for
clutch teeth alignment and shift completion to occur. The
preferred method is with the vehicle rolling 0 to 3 mph (0
to 5 km/h). If the vehicle is moving faster than 3 mph (5
km/h), the transfer case will not allow the shift.
Shifter T-Handle
STARTING AND OPERATING 267
5

Traction Downhill
Shift the transmission into a low gear and the transfer
case to 4WD LOW range. Let the vehicle go slowly down
the hill with all four wheels turning against engine
compression drag. This will permit you to control the
vehicle speed and direction.
When descending mountains or hills, repeated braking
can cause brake fade with loss of braking control. Avoid
repeated heavy braking by downshifting the transmis-
sion whenever possible.
After Driving Off-Road
Off-road operation puts more stress on your vehicle than
does most on-road driving. After going off-road it is
always a good idea to check for damage. That way you
can get any problems taken care of right away and have
your vehicle ready when you need it.
•Completely inspect the underbody of your vehicle.
Check tires, body structure, steering, suspension, and
exhaust system for damage.
•Check threaded fasteners for looseness, particularly on
the chassis, drivetrain components, steering, and sus-
pension. Retighten them, if required, and torque to the
values specified in the Service Manual.
•Check for accumulations of plants or brush. These
things could be a fire hazard. They might hide damage
to fuel lines, brake hoses, axle pinion seals, and
propeller shafts.
•After extended operation in mud, sand, water, or
similar dirty conditions, have brake rotors, wheels,
brake linings, and axle yokes inspected and cleaned as
soon as possible.
STARTING AND OPERATING 279
5

WARNING!
Abrasive material in any part of the brakes may
cause excessive wear or unpredictable braking. You
might not have full braking power when you need it
to prevent an accident. If you have been operating
your vehicle in dirty conditions, get your brakes
checked and cleaned as necessary.
•If you experience unusual vibration after driving in
mud, slush or similar conditions, check the wheels for
impacted material. Impacted material can cause a
wheel imbalance and freeing the wheels of it will
correct the situation.
MULTI DISPLACEMENT SYSTEM (MDS) - 5.7L
Engine Only
This feature offers improved fuel economy by shutting
off four of the engine’s eight cylinders during light load
and cruise conditions. The system is automatic with no
driver inputs or additional driving skills required.
NOTE:The MDS system may take some time to return
to full functionality after a battery disconnect.
280 STARTING AND OPERATING

Loose Fuel Filler Cap Message
If the vehicle diagnostic system determines that the fuel
filler cap is loose, improperly installed, or damaged, a
“CHECK GAS CAP” message will be displayed in the
EVIC (Electronic Vehicle Information Center). Refer to
“Electronic Vehicle Information Center” in Section 4 of
this manual. (See page 186 for more information.) Tighten
the fuel filler cap properly and press the odometer reset
button to turn the message off. If the problem continues,
the message will appear the next time the vehicle is
started. Refer to “Onboard Diagnostic System — OBDII”
in Section 7 of this manual for more information. (See
page 348 for more information.)WARNING!
•Remove the fuel cap (gas cap) slowly to prevent
fuel spray from the filler neck which may cause
injury.
•The volatility of some gasoline may cause a
buildup of pressure in the fuel tank that may
increase while you drive. This pressure can result
in a spray of gasoline and/or vapors when the cap
is removed from a hot vehicle. Removing the cap
slowly allows the pressure to vent and prevents
fuel spray.
•Never have any smoking materials lit in or near
the vehicle when the fuel cap is removed or the
tank filled.
•Never add fuel to the vehicle when the engine is
running.
STARTING AND OPERATING 311
5

If using a manual transmission vehicle for trailer towing,
all starts must be in FIRST gear to avoid excessive clutch
slippage.
Towing Tips — Automatic Transmission
The “D” range can be selected when towing. However, if
frequent shifting occurs while in this range, the ”Tow/
Haul” mode (if equipped) or the “3” range should be
selected. Shift the transmission to Drive position 2 on
more severe grades.
NOTE:Using the ”Tow/Haul” mode (if equipped) or
the “3” range while operating the vehicle under heavy
operating conditions will improve performance and ex-
tend transmission life by reducing excessive shifting and
heat build up. This action will also provide better engine
braking.
The automatic transmission fluid and filter should be
changed if you REGULARLY tow a trailer for more than45 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 — 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:
322 STARTING AND OPERATING

MAINTAINING YOUR VEHICLE
CONTENTS

3.7L Engine...........................345

4.7L Engine...........................346

5.7L Engine...........................347

Onboard Diagnostic System — OBD II........348
▫Loose Fuel Filler Cap Message............348

Emissions Inspection And Maintenance
Programs............................349

Replacement Parts......................350

Dealer Service.........................351
Maintenance Procedures..................351
▫Engine Oil..........................352
▫Drive Belts — Check Condition And
Tensioner...........................355
▫Spark Plugs.........................356
▫Catalytic Converter....................356
▫Crankcase Emission Control System........358
▫Air Cleaner Filter.....................358
▫Maintenance-Free Battery................359
7

▫Air Conditioner Maintenance.............360
▫Power Steering Fluid Check..............361
▫Body Lubrication.....................363
▫Windshield Wiper Blades................363
▫Windshield Washers — Front And Rear.....363
▫Exhaust System......................364
▫Cooling System.......................365
▫Hoses And Vacuum/Vapor Harnesses.......370
▫Brake System........................370
▫Automatic Transmission................372
▫Transfer Case........................375
▫Front/Rear Axle Fluid..................376▫Appearance Care And Protection From
Corrosion...........................377

Fuse Panel...........................381
▫Interior Fuses........................381
▫Underhood Fuses
(Power Distribution Center)..............383
▫Underhood Fuses (Integrated Power Module) . 385

Vehicle Storage........................386

Replacement Bulbs......................387

Fluid Capacities........................388

Fluids, Lubricants, And Genuine Parts........389
▫Engine.............................389
▫Chassis............................390
344 MAINTAINING YOUR VEHICLE

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 Lamp)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.
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 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.
MAINTAINING YOUR VEHICLE 349
7

4. As soon as you turn your key to the ON position, you
will see your 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 off the
ignition key or start the engine. This means that your
vehicle’s OBD system isnot readyand you shouldnot
proceed to the I/M station.
b. The MIL will not flash at all and will remain fully
illuminated until you turn off the ignition key or start
the engine. This means that your vehicle’s OBD system
isreadyand you can proceed to the I/M station.
If your OBD 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
system to update. A recheck with the above test routine
may then indicate that the system is now ready.
Regardless of whether your vehicle’s OBD system is
ready or not ready, if the MIL symbol is illuminated
during normal vehicle operation, you should have your
vehicle serviced before going to the I/M station. The I/M
station can fail your vehicle because the MIL symbol is on
with the engine running.
REPLACEMENT PARTS
Use of genuine Moparparts for normal/scheduled
maintenance and repairs is highly recommended to in-
sure the designed performance. Damage or failures
caused by the use of non-Moparparts for maintenance
and repairs will not be covered by the manufacturer’s
warranty.
350 MAINTAINING YOUR VEHICLE