engine JEEP GRAND CHEROKEE 2012 WK2 / 4.G SRT Repair Manual

ELECTRONIC BRAKE CONTROL SYSTEM
Your vehicle is equipped with an advanced electronic
brake control system that includes the Anti-Lock Brake
System (ABS), Traction Control System (TCS), Brake
Assist System (BAS), Electronic Roll Mitigation (ERM),
and Electronic Stability Control (ESC). All five of these
systems work together to enhance vehicle stability and
control in various driving conditions.
Also, your vehicle is equipped with Trailer Sway Control
(TSC).
Anti-Lock Brake System (ABS)
This system aids the driver in maintaining vehicle control
under adverse braking conditions. The system controls
hydraulic brake pressure to prevent wheel lock-up and
help avoid skidding on slippery surfaces during braking.
WARNING!
The ABS cannot prevent the natural laws of physics
from acting on the vehicle, nor can it increase the
traction afforded by prevailing road conditions. The
ABS cannot prevent collisions, including those re-
sulting from excessive speed in turns, driving on
very slippery surfaces, or hydroplaning. The capa-
bilities of an ABS-equipped vehicle must never be
exploited in a reckless or dangerous manner which
could jeopardize the user’s safety or the safety of
others.
Traction Control System (TCS)
This system monitors the amount of wheel spin of each of
the driven wheels. If wheel spin is detected, brake
pressure is applied to the slipping wheel(s) and engine
power is reduced to provide enhanced acceleration and
stability. A feature of the TCS system, Brake Limited
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Differential (BLD), 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 ESC system is in the “Partial Off” mode.
Refer to “Electronic Stability Control (ESC)” in this
section for further information.
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 applycontinuousbrak-
ing pressure during the stopping sequence (do not
“pump” the brakes). Do not reduce brake pedal pressure
unless braking is no longer desired. Once the brake pedal
is released, the BAS is deactivated.
WARNING!
The 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 collisions, including those re-
sulting from excessive speed in turns, driving on
very slippery surfaces, or hydroplaning. The capa-
bilities of a BAS-equipped vehicle must never be
exploited in a reckless or dangerous manner which
could jeopardize the user’s safety or the safety of
others.
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Electronic Roll Mitigation (ERM)
This system anticipates the potential for wheel lift by
monitoring the driver ’s steering wheel input and the
speed of the vehicle. When ERM determines that the rate
of change of the steering wheel angle and vehicle speed
are sufficient to potentially cause wheel lift, it then
applies the brake of the appropriate wheel and may also
reduce engine power to lessen the chance that wheel lift
will occur. ERM will only intervene during very severe or
evasive driving maneuvers.
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 roadway or striking objects or
other vehicles.WARNING!
Many factors, such as vehicle loading, road condi-
tions and driving conditions, influence the chance
that wheel lift or rollover may occur. ERM cannot
prevent all wheel lift or rollovers, especially those
that involve leaving the roadway or striking objects
or other vehicles. The capabilities of an ERM-
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.
Electronic Stability Control (ESC)
This system enhances directional control and stability of
the vehicle under various driving conditions. ESC cor-
rects for oversteering or understeering of the vehicle by
applying the brake of the appropriate wheel to assist in
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Off” mode is overcome, turn ESC back on by momen-
tarily pressing the “ESC OFF” switch. This may be done
while the vehicle is in motion.
Full Off
This mode is available in TRACK mode only. Refer to
“Selec-Terrain” in “Starting And Operating” for further
information. In this mode, all TCS and ESC stability
features are turned OFF. To enter the “Full Off” mode,
press and hold the “ESC Off” switch for five seconds
while the vehicle is stopped with the engine running.
After five seconds, a chime will sound, the “ESC
Activation/Malfunction Indicator Light” will illuminate,
and theESC OFFmessage will display in the vehicle
odometer. Press and release the TRIP ODOMETER but-
ton located on the instrument cluster to clear this mes-
sage. The “ESC OFF” message may appear in the Elec-
tronic Vehicle Information Center (EVIC). Refer to“Electronic Vehicle Information Center (EVIC)” in “Un-
derstanding Your Instrument Panel” for further informa-
tion. To turn ESC ON again, momentarily press the “ESC
Off” switch.
NOTE:TheESC OFFmessage will display and the
audible chime will sound when the shift lever is moved
into the PARK position from any position other than
PARK and then moved out of the PARK position. This
will occur when the message was previously cleared.
WARNING!
In the ESC “Full Off” mode, the engine torque
reduction and stability features are cancelled. There-
fore, the enhanced vehicle stability offered by ESC is
unavailable.
NOTE:When the ESC is switched OFF, a feature of the
system remains active. This feature controls wheel spin
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across an axle quite similarly to a limited slip differential.
If one wheel on an axle is spinning faster than the other,
the system will apply the brake of the spinning wheel
and allow more engine torque to be applied to the wheel
that is not spinning. To improve the vehicle’s traction
when driving with tire chains, or when starting off in
deep snow, sand, or gravel, it may be desirable to switch
to the “Partial Off” mode by momentarily pressing the
“ESC Off” switch.
WARNING!
With the ESC switched OFF, the enhanced vehicle
stability offered by ESC is unavailable. In an emer-
gency evasive maneuver, the ESC system will not
engage to assist in maintaining stability. The “Full
Off” ESC mode is intended for off-highway or off-
road only.
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 trailer tongue weight recommendations. Refer
to “Trailer Towing” in “Starting and Operating” for
further information. When TSC is functioning, the “ESC
Activation/Malfunction 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
ESC system is in the “Partial Off” mode.
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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.
ESC Activation/Malfunction Indicator Light And
ESC OFF Indicator Light
The “ESC Activation/Malfunction Indicator
Light” in the instrument cluster will come on
when the ignition switch is turned to the ON
position. It should turn off with the engine
running. If the “ESC Activation/Malfunction Indicator
Light” comes on continuously with the engine running, a
malfunction has been detected in the ESC system. If this
light remains on after several ignition cycles, and the
vehicle has been driven several miles (kilometers) atspeeds greater than 30 mph (48 km/h), see your autho-
rized dealer as soon as possible to have the problem
diagnosed and corrected.
The “ESC Activation/Malfunction Indicator Light” (lo-
cated in the instrument cluster) starts to flash as soon as
the tires lose traction and the ESC system becomes active.
The “ESC Activation/Malfunction Indicator Light” also
flashes when TCS is active. If the “ESC Activation/
Malfunction Indicator Light” begins to flash during ac-
celeration, ease up on the accelerator and apply as little
throttle as possible. Be sure to adapt your speed and
driving to the prevailing road conditions.
NOTE:
•The “ESC Activation/Malfunction Indicator Light”
and the “ESC OFF Indicator Light” come on momen-
tarily each time the ignition switch is turned ON.
•Each time the ignition is turned ON, the ESC system
will be ON even if it was turned off previously.
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vehicle. If your vehicle has this option refer to an
authorized tire dealer for the recommended tire rotation
pattern.
If your vehicle is not equipped with an original equip-
ment tire and wheel as a spare, a non-matching tempo-
rary emergency use spare may be equipped with your
vehicle. Temporary use spares are engineered to be used
only with your vehicle. Your vehicle may be equipped
with one of the following types of non-matching tempo-
rary use spares; compact, full size, or limited-use. Do not
install more than one non-matching temporary use spare
tire/wheel on the vehicle at any given time.
CAUTION!
Because of the reduced ground clearance, do not take
your vehicle through an automatic car wash with a
compact, full size or limited-use temporary spare
installed. Damage to the vehicle may result.
Compact Spare Tire – If Equipped
The compact spare is for temporary emergency use only.
You can identify if your vehicle is equipped with a
compact spare by looking at the spare tire description on
the Tire and Loading Information Placard located on the
driver ’s side door opening or on the sidewall of the tire.
Compact spare tire descriptions begin with the letter “T”
or “S” preceding the size designation. Example: T145/
80D18 103M.
T, S = Temporary Spare Tire
Since this tire has limited tread life the original equip-
ment tire should be repaired (or replaced) and reinstalled
on your vehicle at the first opportunity.
Do not install a wheel cover or attempt to mount a
conventional tire on the compact spare wheel, since the
wheel is designed specifically for the compact spare tire.
Do not install more than one compact spare tire and
wheel on the vehicle at any given time
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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...................MRXC4W4MA4
Canada.....................2546A-C4W4MA4
FUEL REQUIREMENTS
6.4L Engine
The 6.4L engine is designed to meet all
emissions regulations and provide excel-
lent fuel economy and performance when
using high-quality premium unleaded
gasoline with an octane rating of 91 or
higher.
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 experi-
ence these symptoms, try another brand of gasoline
before considering service for the vehicle.
Over 40 auto manufacturers worldwide have issued and
endorsed consistent gasoline specifications (the World-
wide Fuel Charter, WWFC) which define fuel properties
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necessary to deliver enhanced emissions, performance,
and durability for your vehicle. The manufacturer recom-
mends the use of gasolines that meet 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 gasolines contain oxygenates and are spe-
cifically blended to reduce vehicle emissions and im-
prove air quality.
The manufacturer supports the use of reformulated gaso-
lines. Properly blended reformulated gasolines 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 thewinter months to reduce carbon monoxide emissions.
Fuels blended with these oxygenates may be used in
your vehicle.
CAUTION!
Do not use gasolines containing Methanol or E-85
Ethanol. Use of these blends may result in starting
and driveability problems and may damage critical
fuel system components.
Problems that result from using methanol/gasoline or
E-85 ethanol 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.
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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 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 emissions 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 whether
the gasoline contains MMT. It is even more important to
look for gasoline without MMT in Canada, because MMT
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