engine JEEP COMMANDER 2010 1.G Repair Manual

FUEL REQUIREMENTS
3.7 Engine
All engines (except 5.7L engines) are de-
signed to meet all emissions regulations
and provide excellent fuel economy and
performance when using high-quality un-
leaded “regular” gasoline having an oc-
tane rating of 87. The use of premium
gasoline is not recommended, as it will not provide any
benefit over regular gasoline in these engines.
5.7L Engine
The 5.7L engine is designed to meet all
emissions regulations and provide satisfac-
tory fuel economy and performance when
using high-quality unleaded gasoline hav-
ing an octane range of 87 to 89. The manu-
facturer recommends the use of 89 octane for optimum performance. The use of premium gasoline
is not recommended, as it will not provide any benefit
over regular gasoline in these engines.
Light spark knock at low engine speeds is not harmful to
your engine. However, continued heavy spark knock at
high speeds can cause damage, and immediate service is
required.
Poor quality gasoline can cause problems such as hard
starting, stalling and hesitations. If you experience these
symptoms, try another brand of gasoline before consid-
ering service for the vehicle.
Over 40 auto manufacturers worldwide have issued and
endorsed consistent gasoline specifications (the World-
wide Fuel Charter, WWFC) to define fuel properties
necessary to deliver enhanced emissions, performance,
and durability for your vehicle. The manufacturer recom-
mends the use of gasoline that meets the WWFC speci-
fications, if they are available.
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Reformulated Gasoline
Many areas of the country require the use of cleaner
burning gasoline referred to as “Reformulated Gasoline.”
Reformulated gasoline contains oxygenates, and are spe-
cifically blended to reduce vehicle emissions and im-
prove air quality.
The manufacturer supports the use of reformulated gaso-
line. Properly blended reformulated gasoline will pro-
vide excellent performance and durability of engine and
fuel system components.
Gasoline/Oxygenate Blends
Some fuel suppliers blend unleaded gasoline with oxy-
genates such as 10% Ethanol, MTBE, and ETBE. Oxygen-
ates are required in some areas of the country during the
winter months to reduce carbon monoxide emissions.
Fuels blended with these oxygenates may be used in
your vehicle.
CAUTION!
DO NOT use gasoline containing Methanol. Use of
these blends may result in starting and drivability
problems and may damage critical fuel system com-
ponents.
Problems that result from using Methanol/gasoline
blends are not the responsibility of the manufacturer.
While MTBE is an oxygenate made from Methanol, it
does not have the negative effects of Methanol.
E-85 Usage In Non-Flex Fuel Vehicles
Non-FFV vehicles are compatible with gasoline contain-
ing 10% Ethanol (E10). Gasoline with higher Ethanol
content may void the vehicle’s warranty.
If a Non-FFV vehicle is inadvertently fueled with E-85
fuel, the engine will have some or all of these symptoms:
•operate in a lean mode
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•OBD II “Malfunction Indicator Light” on
•poor engine performance
•poor cold start and cold drivability
•increased risk for fuel system component corrosion
To fix a Non-FFV vehicle inadvertently fueled once with
E-85 perform the following:
•drain the fuel tank (see your authorized dealer)
•change the engine oil and oil filter
•disconnect and reconnect the battery to reset the
engine controller memory
More extensive repairs will be required for prolonged
exposure to E-85 fuel.
MMT In Gasoline
MMT is a manganese containing metallic additive that is
blended into some gasoline to increase octane. Gasoline blended with MMT provides no performance advantage
beyond gasoline of the same octane number without
MMT. Gasoline blended with MMT reduces spark plug
life and reduces emission system performance in some
vehicles. The manufacturer recommends that gasoline
without MMT be used in your vehicle. The MMT content
of gasoline may not be indicated on the gasoline pump,
therefore, you should ask your gasoline retailer if the
gasoline contains MMT.
It is even more important to look for gasoline without
MMT in Canada, because MMT can be used at levels
higher than those allowed in the United States.
MMT is prohibited in Federal and California reformu-
lated gasoline.
Materials Added To Fuel
All gasoline sold in the United States is required to
contain effective detergent additives. Use of additional
detergents or other additives is not needed under normal
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conditions and would result in additional cost. Therefore,
you should not have to add anything to the fuel.
Fuel System Cautions
CAUTION!
Follow these guidelines to maintain your vehicle’s
performance:
•The use of leaded gas is prohibited by Federal law.
Using leaded gasoline can impair engine performance
and damage the emission control system.
•An out-of-tune engine, or certain fuel or ignition
malfunctions, can cause the catalytic converter to
overheat. If you notice a pungent burning odor or
some light smoke, your engine may be out of tune or
malfunctioning and may require immediate service.
Contact your authorized dealer for service assistance.
•The use of fuel additives which are now being sold as
octane enhancers is not recommended. Most of these
products contain high concentrations of Methanol.
Fuel system damage or vehicle performance problems
resulting from the use of such fuels or additives is not
the responsibility of the manufacturer.
NOTE: Intentional tampering with emissions control
systems can result in civil penalties being assessed
against you.
Carbon Monoxide Warnings
WARNING!
Carbon monoxide (CO) in exhaust gases is deadly.
Follow the precautions below to prevent carbon
monoxide poisoning.
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•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
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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.
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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.
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All trailer hitches should be professionally installed on
your vehicle.
Trailer Towing Weights (Maximum Trailer Weight Ratings)
The following chart provides the maximum trailer weight ratings towable for your given drivetrain.
Engine Model GCWR (Gross Com-bined Wt. Rating)Frontal Area Max. GTW (Gross
Trailer Wt.)Max. Trailer
Tongue Wt. (See Note)
3.7L 4x2 8,700 lbs (3 946 kg) 40 sq ft (3.72 sq m)3,500 lbs (1 587 kg) 350 lbs (159 kg)
3.7L 4x4 8,800 lbs (3 991 kg) 40 sq ft (3.72 sq m)3,500 lbs (1 587 kg) 350 lbs (159 kg)
5.7L 4x2 12,700 lbs (5 760 kg) 60 sq ft (5.57 sq m)7,400 lbs (3 356 kg) 740 lbs (336 kg)
5.7L 4x4 12,700 lbs (5 760 kg) 60 sq ft (5.57 sq m)7,200 lbs (3 266 kg) 720 lbs (327 kg)
Refer to local laws for maximum trailer towing speeds.
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•When hauling cargo or towing a trailer, do not over-
load your vehicle or trailer. Overloading can cause a
loss of control, poor performance or damage to brakes,
axle, engine, transmission, steering, suspension, chas-
sis structure or tires.
•Safety chains must always be used between your
vehicle and trailer. Always connect the chains to the
hook retainers of the vehicle hitch. Cross the chains
under the trailer tongue and allow enough slack for
turning corners.
•Vehicles with trailers should not be parked on a grade.
When parking, apply the parking brake on the tow
vehicle. Put the tow vehicle transmission in PARK. For
four-wheel drive vehicles, make sure the transfer case
is not in NEUTRAL. Always, block orchockthe
trailer wheels.
•GCWR must not be exceeded.
•Total weight must be distributed between the tow
vehicle and the trailer such that the following four
ratings are not exceeded:
1. GVWR
2. GTW
3. GAWR
4. Trailer tongue weight rating for the trailer hitch
utilized (This requirement may limit the ability to
always achieve the 10% to 15% range of tongue weight
as a percentage of total trailer weight).
Towing Requirements — Tires

Do not attempt to tow a trailer while using a compact
spare tire.
Proper tire inflation pressures are essential to the safe
and satisfactory operation of your vehicle. Refer to
“Tires–General Information” in this section.
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Towing Tips
Before setting out on a trip, practice turning, stopping
and backing the trailer in an area away from heavy
traffic.
Automatic Transmission
The DRIVE range can be selected when towing. How-
ever, if frequent shifting occurs while in this range, the
TOW/HAUL mode (if equipped) or a lower gear range
should be selected.
NOTE:Using the TOW/HAUL mode (if equipped) or a
lower gear range while operating the vehicle under
heavy operating conditions, will improve performance
and extend transmission life by reducing excessive shift-
ing and heat buildup. This action will also provide better
engine braking. The transmission fluid and filter should be changed if
you REGULARLY tow a trailer for more than 45 minutes
of continuous operation. Refer to the “Maintenance
Schedule” in Section 8 for the proper maintenance inter-
vals.
NOTE:
Check the transmission fluid level before towing
(5.7L engine).
Electronic Speed Control — If Equipped

Do not 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.
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