engine JEEP WRANGLER 2009 JK / 3.G Workshop Manual

system functions similar to a limited slip differential and
controls the wheel spin across a driven axle. If one wheel
on a driven axle is spinning faster than the other, the
system will apply the brake of the spinning wheel. This
will allow more engine torque to be applied to the wheel
that is not spinning. This feature remains active even if
TCS and ESP are in either the “Partial Off” or “Full Off”
modes. Refer to “ESP (Electronic Stability Program)” in
this section.
Brake Assist System (BAS)
The BAS is designed to optimize the vehicle’s braking
capability during emergency braking maneuvers. The
system detects an emergency braking situation by sens-
ing the rate and amount of brake application and then
applies optimum pressure to the brakes. This can help
reduce braking distances. The BAS complements the
anti-lock brake system (ABS). Applying the brakes very
quickly results in the best BAS assistance. To receive thebenefit of the system, you must apply continuous brak-
ing pressure during the stopping sequence. Do not
reduce brake pedal pressure unless braking is no longer
desired. Once the brake pedal is released, the BAS is
deactivated.
WARNING!
The Brake Assist System (BAS) cannot prevent the
natural laws of physics from acting on the vehicle,
nor can it increase the traction afforded by prevailing
road conditions. The BAS cannot prevent accidents,
including those resulting from excessive speed in
turns, driving on very slippery surfaces, or hydro-
planing. Only a safe, attentive, and skillful driver can
prevent accidents. The capabilities of a BAS-
equipped vehicle must never be exploited in a reck-
less or dangerous manner which could jeopardize the
user’s safety or the safety of others.
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Towing with HSA
HSA will provide assistance when starting on a grade
when pulling a trailer.
WARNING!
•If you use a trailer brake controller with your
trailer, your trailer brakes may be activated and
deactivated with the brake switch. If so, when the
brake pedal is released there may not be enough
brake pressure to hold the vehicle and trailer on a
hill and this could cause a collision with another
vehicle or object behind you. In order to avoid
rolling down the hill while resuming acceleration,
manually activate the trailer brake prior to releas-
ing the brake pedal. Always remember the driver
is responsible for braking the vehicle.(Continued)
WARNING! (Continued)
•HSA is not a parking brake. If you stop the vehicle
on a hill without putting the transmission in
PARK and using the parking brake, it will roll
down the hill and could cause a collision with
another vehicle or object. Always remember to use
the parking brake while parking on a hill, and that
the driver is responsible for braking the vehicle.
HSA Off
If you wish to turn off the HSA system, follow this
procedure:
1. Start with the engine off and vehicle in PARK (auto-
matic transmission) or NEUTRAL with clutch out
(manual transmission) with wheels straight. Apply park-
ing brake on manual transmission vehicle.
2. Start the engine.
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3. With the engine running, the brake applied, and the
clutch out, rotate the steering wheel 180° counterclock-
wise from center.
4. Press the ESP OFF switch four times within twenty
seconds.
5. Rotate the steering wheel 360° clockwise (180° clock-
wise from center).
6. Cycle ignition switch OFF then ON.
7. If the sequence was completed properly, the “ESP/
TCS Indicator Light” will blink several times to confirm
HSA is off.
Steps 1-7 must be completed within 90 seconds to turn off
HSA. Repeat steps 1-7 to re-enable HSA functionality.
Electronic Roll Mitigation (ERM)
This system anticipates the potential for wheel lift by
monitoring the driver ’s steering wheel input and thespeed of the vehicle. When ERM determines that the rate
of change of the steering wheel angle and vehicle’s speed
are sufficient to potentially cause wheel lift, it applies the
appropriate brake and may reduce engine power to
lessen the chance that wheel lift will occur. ERM will only
intervene during very severe or evasive driving maneu-
vers.
Electronic Roll Mitigation (ERM) can only reduce the
chance of wheel lift occurring during severe or evasive
driving maneuvers. It cannot prevent wheel lift due to
other factors such as road conditions, leaving the road-
way or striking objects or other vehicles.
NOTE:
Anytime the ESP system is in the “Full Off”
mode, ERM is disabled. Refer to ESP (Electronic Stability
Program) for a complete explanation of the available ESP
modes.
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WARNING!
Many factors, such as vehicle loading, road condi-
tions and driving conditions, influence the chance
that wheel lift or rollover may occur. Electronic Roll
Mitigation (ERM) cannot prevent all wheel lift or
rollovers, especially those that involve leaving the
roadway or striking objects or other vehicles. Only a
safe, attentive, and skillful driver can prevent acci-
dents. The capabilities of an ERM-equipped vehicle
must never be exploited in a reckless or dangerous
manner which could jeopardize the user’s safety or
the safety of others.
Electronic Stability Program (ESP)
This system enhances directional control and stability of
the vehicle under various driving conditions. The ESP
corrects for over/under steering of the vehicle by apply-
ing the brake of the appropriate wheel to assist incounteracting the over/under steer condition. Engine
power may also be reduced to help the vehicle maintain
the desired path.
ESP uses sensors in the vehicle to determine the vehicle
path intended by the driver and compares it to the actual
path of the vehicle. When the actual path does not match
the intended path, ESP applies the brake of the appropri-
ate wheel to assist in counteracting the oversteer or
understeer condition.
•Oversteer - when the vehicle is turning more than
appropriate for the steering wheel position.
•Understeer - when the vehicle is turning less than
appropriate for the steering wheel position.
The “ESP/TCS Indicator Light” (located in the instru-
ment cluster), 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
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STARTING AND OPERATING 325

ESP function normally. This mode is intended to be used
if the vehicle is in deep snow, sand, or gravel conditions
and more wheel spin than ESP would normally allow is
required to gain traction. To turn ESP on again, momen-
tarily press the ESP OFF switch. This will restore the
normal “ESP On” mode of operation.NOTE:
To improve the vehicle’s traction when driving
with snow chains, or starting off in deep snow, sand, or
gravel, it may be desirable to switch to the “Partial Off”
mode by pressing the ESP OFF switch. Once the situation
requiring ESP to be switched to the “Partial Off” mode is
overcome, turn ESP back on by momentarily pressing the
ESP OFF switch. This may be done while the vehicle is in
motion.
ESP Off (4H Range Only)
This mode is intended for off-highway or off-road use
when ESP stability features could inhibit vehicle maneu-
verability due to trail conditions. This mode is entered by
pressing and holding the ESP OFF switch for five seconds
when the vehicle is stopped and the engine is running. In
this mode, all ESP and TCS stability features are turned
off except for the “limited slip” feature described in the
TCS section. After five seconds, a chime will sound, the
“ESP/TCS Indicator Light” will illuminate, and the “ESP
OFF message will appear in the odometer. Refer to
ESP OFF Switch
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9. Turn the steering wheel back to center.
10. Press and hold the ESP OFF button for seven seconds.
11. Cycle the ignition key to OFF.
After performing the ESP disable procedure correctly,
“ESP OFF” will be displayed in the odometer for approxi-
mately 12 seconds each time the ignition is moved to ON.
Repeating the ESP disable procedure will re-enable nor-
mal ESP operation.
ESP/BAS Warning Light
The malfunction indicator lamp for the ESP is
combined with the BAS indicator. The “ESP/
BAS Warning Light” in the instrument cluster
comes on when the ignition switch is turned to
the “ON” position. It 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, or both. If this light
remains on after several ignition cycles, and the vehicle
has been driven several miles/kilometers at speeds
greater than 30 mph (48 km/h), see your authorized
dealer as soon as possible to have the problem diagnosed
and corrected.
NOTE:
•The “ESP/BAS Warning Light” comes on momentarily
each time the ignition switch is turned ON.
•Each time the ignition is turned ON, the ESP System
will be ON even if it was previously turned off.
•The ESP Control System will make buzzing or clicking
sounds when it is active. This is normal; the sounds
will stop when ESP becomes inactive following the
maneuver that caused the ESP activation.
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Trailer Sway Control (TSC)
TSC uses sensors in the vehicle to recognize an exces-
sively swaying trailer and will take the appropriate
actions to attempt to stop the sway. The system may
reduce engine power and apply the brake of the appro-
priate wheel(s) to counteract the sway of the trailer. TSC
will become active automatically once an excessively
swaying trailer is recognized. No driver action is re-
quired. Note that TSC cannot stop all trailers from
swaying. Always use caution when towing a trailer and
follow the tongue weight recommendations. Refer to
“Trailer Towing” in Section 5 of this manual for more
information on towing a trailer with your vehicle. When
TSC is functioning, the “ESP/TCS Indicator Light” will
flash, the engine power may be reduced and you may
feel the brakes being applied to individual wheels to
attempt to stop the trailer from swaying. TSC is disabled
when the ESP system is in the “Partial Off” or “Full Off”
modes.WARNING!
If TSC activates while driving, slow the vehicle
down, stop at the nearest safe location, and adjust the
trailer load to eliminate trailer sway.
332 STARTING AND OPERATING

vehicle in place of the spare tire, the TPMS will update
automatically and the “Tire Pressure Monitoring Tell-
tale Light” will turn OFF, as long as no tire pressure is
below the low-pressure warning limit in any of the
four active road tires. The vehicle may need to be
driven for up to 20 minutes above 15 mph (25 km/h)
in order for the TPMS to receive this information.
General Information
This device complies with part 15 of the FCC rules and
RSS 210 of Industry Canada. Operation is subject to the
following conditions:
•This device may not cause harmful interference.
•This device must accept any interference received,
including interference that may cause undesired
operation.The tire pressure sensors are covered under one of the
following licenses:
United States
..................... KR5S120123
Canada ........................ 2671-S120123
FUEL REQUIREMENTS
All engines are designed to meet all emis-
sions regulations and provide excellent
fuel economy and performance when us-
ing high quality unleaded “regular” gaso-
line having an octane rating of 87. 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.
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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 manufacturer’s 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.
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 for the 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 gasolines containing Methanol. Use of
these blends may result in starting and drivability
problems and may damage critical fuel system com-
ponents.
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STARTING AND OPERATING 357

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
•OBD II “Malfunction Indicator Light” on
•poor engine performance
•poor cold start and cold drivability
•increased risk for fuel system component corrosionTo 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 the octane num-
ber. Gasoline blended with MMT offers no performance
advantage beyond gasoline of the same octane number
without MMT. Gasoline blended with MMT has shown
to reduce sparkplug life and reduce emission system
performance in some vehicles. The manufacturer recom-
mends that gasoline without MMT be used in your
358 STARTING AND OPERATING