2012 JEEP GRAND CHEROKEE ECU

Installing and Removing the ENGINE
START/STOP Button
Installing the Button
1. Remove the key fob from the ignition switch.
2. Insert the ENGINE START/STOP button into
the ignition switch with the lettering facing up
and readable.
3. Press firmly on the center of the button to
secure it into position.
Removing the Button
1. The ENGINE START/STOP button can be
removed from the ignition switch for key fob
use.
2. Insert the metal part of the emergency key
under the chrome bezel at the 6 o’clock posi-
tion and gently pry the button loose.
NOTE:
The ENGINE START/STOP button should
only be removed or inserted with the ignition
in the LOCK position (OFF position for Key-
less Enter-N-Go).Normal Starting
Using the ENGINE START/STOP Button
NOTE:
Normal starting of either a cold or a warm
engine is obtained without pumping or
pressing the accelerator pedal.
To start the engine, the transmission must be in
PARK or NEUTRAL. Press and hold the brake
pedal while pressing the ENGINE START/STOP
button once. The system takes over and at-
tempts to start the vehicle. If the vehicle fails to
start, the starter will disengage automatically
after 10 seconds. If you wish to stop the crank-
ing of the engine prior to the engine starting,
press the button again.
To Turn Off the Engine Using ENGINE
START/STOP Button
1. Place the shift lever in PARK, then press and
release the ENGINE START/STOP button.
2. The ignition switch will return to the OFF
position.
3. If the shift lever is not in PARK, the ENGINE
START/STOP button must be held for two sec-onds and vehicle speed must be above 5 mph
(8 km/h) before the engine will shut off. The
ignition switch position will remain in the ACC
position until the shift lever is in PARK and the
button is pressed twice to the OFF position. If
the shift lever is not in PARK and the ENGINE
START/STOP button is pressed once, the EVIC
(if equipped) will display a “Vehicle Not In Park”
message and the engine will remain running.
Never leave a vehicle out of the PARK position,
or it could roll.
NOTE:
If the ignition switch is left in the ACC or
RUN (engine not running) position and the
transmission is in PARK, the system will
automatically time out after 30 minutes of
inactivity and the ignition will switch to the
OFF position.
Keyless Enter-N-Go Functions – With
Driver’s Foot OFF the Brake Pedal (In
PARK or NEUTRAL Position)
The Keyless Enter-N-Go feature operates simi-
lar to an ignition switch. It has four positions,
OFF, ACC, RUN and START. To change the
217

AUTOMATIC TRANSMISSION
CAUTION!
Damage to the transmission may occur if the
following precautions are not observed:
•Shift into PARK only after the vehicle has
come to a complete stop.
• Shift into or out of REVERSE only after the
vehicle has come to a complete stop and
the engine is at idle speed.
• Do not shift between PARK, REVERSE,
NEUTRAL, or DRIVE when the engine is
above idle speed.
• Before shifting into any gear, make sure
your foot is firmly pressing the brake pedal.
NOTE:
You must press and hold the brake pedal
while shifting out of PARK.
WARNING!
• Unintended movement of a vehicle could
injure those in or near the vehicle. As with
all vehicles, you should never exit a vehicle
while the engine is running. Before exiting a
vehicle, always apply the parking brake,
shift the transmission into PARK, and re-
move the key fob. Once the key fob is
removed, the shift lever is locked in the
PARK position, securing the vehicle
against unwanted movement.
• It is dangerous to move the shift lever out of
PARK or NEUTRAL if the engine speed is
higher than idle speed. If your foot is not
firmly pressing the brake pedal, the vehicle
could accelerate quickly forward or in re-
verse. You could lose control of the vehicle
and hit someone or something. Only shift
into gear when the engine is idling normally
and when your foot is firmly pressing the
brake pedal.
(Continued)WARNING!(Continued)
• When leaving the vehicle, always remove
the key fob and lock your vehicle.
• Never leave children alone in a vehicle, or
with access to an unlocked vehicle. Allow-
ing children to be in a vehicle unattended is
dangerous for a number of reasons. A child
or others could be seriously or fatally in-
jured.
• Children should be warned not to touch the
parking brake, brake pedal or the shift
lever. Do not leave the key fob in or near
the vehicle, and do not leave Keyless
Enter-N-Go in the ACC or ON/RUN mode.
A child could operate power windows, other
controls, or move the vehicle.
Key Ignition Park InterlockThis vehicle is equipped with a Key Ignition
Park Interlock which requires the shift lever to
be placed in PARK before the ignition switch
can be turned to the LOCK/OFF position. The
key fob can only be removed from the ignition
221

When parking on a hill, apply the parking brake
before placing the shift lever in PARK, other-
wise the load on the transmission locking
mechanism may make it difficult to move the
shift lever out of PARK. As an added precau-
tion, turn the front wheels toward the curb on a
downhill grade and away from the curb on an
uphill grade.
WARNING!
•Never use the PARK position as a substi-
tute for the parking brake. Always apply the
parking brake fully when parked to guard
against vehicle movement and possible
injury or damage.
• Your vehicle could move and injure you and
others if it is not completely in PARK.
Check by trying to move the shift lever
rearward (with the brake pedal released),
after you have placed it in PARK. Make
sure the transmission is in PARK before
leaving the vehicle.
(Continued)
WARNING!(Continued)
•It is dangerous to move the shift lever out of
PARK or NEUTRAL if the engine speed is
higher than idle speed. If your foot is not firmly
pressing the brake pedal, the vehicle could
accelerate quickly forward or in reverse. You
could lose control of the vehicle and hit some-
one or something. Only shift into gear when
the engine is idling normally and when your
foot is firmly pressing the brake pedal.
• Unintended movement of a vehicle could
injure those in or near the vehicle. As with
all vehicles, you should never exit a vehicle
while the engine is running. Before exiting a
vehicle, always apply the parking brake,
shift the transmission into PARK, and re-
move the key fob. Once the key fob is
removed, the shift lever is locked in the
PARK position, securing the vehicle
against unwanted movement.
• When leaving the vehicle, always remove
the key fob and lock your vehicle.
(Continued)
WARNING!(Continued)
• Never leave children alone in a vehicle, or
with access to an unlocked vehicle.
• Allowing children to be in a vehicle unat-
tended is dangerous for a number of rea-
sons. A child or others could be seriously or
fatally injured. Children should be warned
not to touch the parking brake, brake pedal
or the shift lever. Do not leave the key fob in
or near the vehicle, and do not leave Key-
less Enter-N-Go in the ACC or ON/RUN
mode. A child could operate power win-
dows, other controls, or move the vehicle.
CAUTION!
•Before moving the shift lever out of PARK,
you must turn the ignition switch from the
LOCK/OFF position to the ON/RUN posi-
tion, and also press the brake pedal. Oth-
erwise, damage to the shift lever could
result.
(Continued)
223

of which forward gear is selected. PARK, RE-
VERSE, and NEUTRAL will continue to operate.
The Malfunction Indicator Light (MIL) may be
illuminated. Limp Home Mode allows the ve-
hicle to be driven to an authorized dealer for
service without damaging the transmission.
In the event of a momentary problem, the
transmission can be reset to regain all forward
gears by performing the following steps:
1. Stop the vehicle.
2. Shift the transmission into PARK.
3. Turn the ignition switch to the LOCK/OFF
position.
4. Wait approximately 10 seconds.
5. Restart the engine.
6. Shift into the desired gear range. If the
problem is no longer detected, the transmis-
sion will return to normal operation.
NOTE:
Even if the transmission can be reset, we
recommend that you visit your authorized
dealer at your earliest possible conve-nience. Your authorized dealer has diagnos-
tic equipment to determine if the problem
could recur.
If the transmission cannot be reset, authorized
dealer service is required.
Electronic Range Select (ERS) Operation
The Electronic Range Select (ERS) shift control
allows the driver to limit the highest available
gear when the shift lever is in the DRIVE
position. For example, if you shift the transmis-
sion into 3 (third gear), the transmission will
never shift above third gear, but will shift down
into second and first gear normally.
You can switch between DRIVE and ERS mode
at any vehicle speed. When the shift lever is in
the DRIVE position, the transmission will oper-
ate automatically, shifting between all available
gears. Tapping the shift lever to the left (-) will
downshift the transmission, activate ERS mode,
display the current gear in the instrument clus-
ter, and maintain that gear as the top available
gear. Once in ERS mode, tapping the shift lever
to the left (-) or right (+) will change the top
available gear.
To exit ERS mode, simply press and hold the
shift lever to the right (+) until “D” is once again
displayed in the shift lever position indicator in
the instrument cluster.
WARNING!
Do not downshift for additional engine braking
on a slippery surface. The drive wheels could
lose their grip and the vehicle could skid,
causing an accident or personal injury.
Screen Display
12 34D
Actual Gear(s)
Allowed 1 1-2 1-3 1-4 1-5
NOTE:
To select the proper gear position for maxi-
mum deceleration (engine braking), simply
press and hold the shift lever to the left (-).
The transmission will shift to the range from
which the vehicle can best be slowed down.
225

When parking on a hill, apply the parking brake
before placing the shift lever in PARK, other-
wise the load on the transmission locking
mechanism may make it difficult to move the
shift lever out of PARK. As an added precau-
tion, turn the front wheels toward the curb on a
downhill grade and away from the curb on an
uphill grade.
WARNING!
•Never use the PARK position as a substi-
tute for the parking brake. Always apply the
parking brake fully when parked to guard
against vehicle movement and possible
injury or damage.
• Your vehicle could move and injure you and
others if it is not completely in PARK.
Check by trying to move the shift lever
rearward (with the brake pedal released),
after you have placed it in PARK. Make
sure the transmission is in PARK before
leaving the vehicle.
(Continued)
WARNING!(Continued)
•It is dangerous to move the shift lever out of
PARK or NEUTRAL if the engine speed is
higher than idle speed. If your foot is not firmly
pressing the brake pedal, the vehicle could
accelerate quickly forward or in reverse. You
could lose control of the vehicle and hit some-
one or something. Only shift into gear when
the engine is idling normally and when your
foot is firmly pressing the brake pedal.
• Unintended movement of a vehicle could
injure those in or near the vehicle. As with
all vehicles, you should never exit a vehicle
while the engine is running. Before exiting a
vehicle, always apply the parking brake,
shift the transmission into PARK, and re-
move the key fob. Once the key fob is
removed, the shift lever is locked in the
PARK position, securing the vehicle
against unwanted movement.
• When leaving the vehicle, always remove
the key fob and lock your vehicle.
(Continued)
WARNING!(Continued)
• Never leave children alone in a vehicle, or
with access to an unlocked vehicle. Allow-
ing children to be in a vehicle unattended is
dangerous for a number of reasons. A child
or others could be seriously or fatally in-
jured. Children should be warned not to
touch the parking brake, brake pedal or the
shift lever. Do not leave the key fob in or
near the vehicle, and do not leave Keyless
Enter-N-Go in the ACC or ON/RUN mode.
A child could operate power windows, other
controls, or move the vehicle.
CAUTION!
•Before moving the shift lever out of PARK,
you must turn the ignition switch from the
LOCK/OFF position to the ON/RUN posi-
tion, and also press the brake pedal. Oth-
erwise, damage to the shift lever could
result.
(Continued)
227

If the transmission operating temperature ex-
ceeds normal operating limits, the powertrain
controller will modify the transmission shift
schedule and expand the range of torque con-
verter clutch engagement. This is done to pre-
vent transmission damage due to overheating.
If the transmission becomes extremely hot, the
“Transmission Temperature Warning Light” may
illuminate and the transmission may downshift
out of Overdrive until the transmission cools
down.
NOTE:
Use caution when operating a heavily
loaded vehicle at low speeds (such as tow-
ing a trailer up a steep grade, or in stop-
and-go traffic) during hot weather. In these
conditions, torque converter slip can im-
pose a significant additional heat load on
the cooling system. Downshifting the trans-
mission to the lowest possible gear (when
climbing a grade), or shifting to NEUTRAL
(when stopped in heavy traffic) can help to
reduce this excess heat generation.
During cold temperatures, transmission opera-
tion may be modified depending on engine andtransmission temperature as well as vehicle
speed. This feature improves warm up time of
the engine and transmission to achieve maxi-
mum efficiency. Engagement of both the torque
converter clutch and the top overdrive gear are
inhibited until the transmission fluid is warm
(refer to the “Note” under “Torque Converter
Clutch” in this section). During extremely cold
temperatures (-16°F [-27°C] or below), opera-
tion may briefly be limited to first and direct
gears only. Normal operation will resume once
the transmission temperature has risen to a
suitable level.
Transmission Limp Home Mode
Transmission function is monitored electroni-
cally for abnormal conditions. If a condition is
detected that could result in transmission dam-
age, Transmission Limp Home Mode is acti-
vated. In this mode, the transmission remains in
direct gear regardless of which forward gear is
selected. PARK, REVERSE, and NEUTRAL will
continue to operate. The Malfunction Indicator
Light (MIL) may be illuminated. Limp Home
Mode allows the vehicle to be driven to an
authorized dealer for service without damaging
the transmission.
In the event of a momentary problem, the
transmission can be reset to regain all forward
gears by performing the following steps:
1. Stop the vehicle.
2. Shift the transmission into PARK.
3. Turn the ignition switch to the LOCK/OFF
position.
4. Wait approximately 10 seconds.
5. Restart the engine.
6. Shift into the desired gear range. If the
problem is no longer detected, the transmis-
sion will return to normal operation.
NOTE:
Even if the transmission can be reset, we
recommend that you visit your authorized
dealer at your earliest possible conve-
nience. Your authorized dealer has diagnos-
tic equipment to determine if the problem
could recur.
If the transmission cannot be reset, authorized
dealer service is required.
229

WARNING!
Fast spinning tires can be dangerous. Forces
generated by excessive wheel speeds may
cause tire damage or failure. A tire could
explode and injure someone. Do not spin your
vehicle’s wheels faster than 30 mph (48 km/h)
when you are stuck, and do not let anyone
near a spinning wheel, no matter what the
speed.
Tire ChainsUse of traction devices require sufficient tire-to-
body clearance. Follow these recommenda-
tions to guard against damage.
•Install on Rear Tires Only
• Due to limited clearance, use SAE class “S”
low profile cables or traction devices only.
Security Chain Company (SCC) Super Z6
#SZ 441 cables or equivalent are recom-
mended.
WARNING!
Using tires of different size and type (M+S,
Snow) between front and rear axles can
cause unpredictable handling. You could lose
control and have a collision.
CAUTION!
To avoid damage to your vehicle or tires,
observe the following precautions:
• Because of restricted traction device clear-
ance between tires and other suspension
components, it is important that only trac-
tion devices in good condition are used.
Broken devices can cause serious dam-
age. Stop the vehicle immediately if noise
occurs that could indicate device breakage.
Remove the damaged parts of the device
before further use.
• Install device as tightly as possible and
then retighten after driving about 0.5 mile
(0.8 km).
• Do not exceed 30 mph (48 km/h).
(Continued)
CAUTION!(Continued)
• Drive cautiously and avoid severe turns
and large bumps, especially with a loaded
vehicle.
• Do not drive for prolonged period on dry
pavement.
• Observe the traction device manufacturer’s
instructions on the method of installation,
operating speed, and conditions for use.
Always use the suggested operating speed
of the device manufacturer’s if it is less than
30 mph (48 km/h).
• Do not use traction devices on a compact
spare tire.
Treadwear IndicatorsThese indicators are narrow strips 1/16 in
(1.6 mm) thick and are found in the tread
pattern grooves.
When the tread pattern is worn down to these
treadwear indicators, the tires should be re-
placed.
254

the maximum combined weight of occu-
pants and cargo for your vehicle.
Towing RequirementsTo promote proper break-in of your new vehicle
drivetrain components, the following guidelines
are recommended.
CAUTION!
•Do not tow a trailer at all during the first
500 miles (805 km) the new vehicle is
driven. The engine, axle or other parts
could be damaged.
• Then, during the first 500 miles (805 km)
that a trailer is towed, do not drive over
50 mph (80 km/h) and do not make starts at
full throttle. This helps the engine and other
parts of the vehicle wear in at the heavier
loads.
Perform the maintenance listed in the “Mainte-
nance Schedule.” Refer to “Maintenance
Schedule” for the proper maintenance inter-
vals. When towing a trailer, never exceed the
GAWR or GCWR ratings.
WARNING!
Improper towing can lead to an injury acci-
dent. Follow these guidelines to make your
trailer towing as safe as possible:
•
Make certain that the load is secured in the
trailer and will not shift during travel. When
trailering cargo that is not fully secured, dy-
namic load shifts can occur that may be
difficult for the driver to control. You could lose
control of your vehicle and have an accident.
• When hauling cargo or towing a trailer, do
not overload your vehicle or trailer. Over-
loading can cause a loss of control, poor
performance or damage to brakes, axle,
engine, transmission, steering, suspen-
sion, chassis structure or tires.
• Safety chains must always be used be-
tween your vehicle and trailer. Always con-
nect the chains to the hook retainers of the
vehicle hitch. Cross the chains under the
trailer tongue and allow enough slack for
turning corners.
(Continued)
WARNING!(Continued)
• Vehicles with trailers should not be parked
on a grade. When parking, apply the park-
ing brake on the tow vehicle. Put the tow
vehicle transmission in PARK. For four-
wheel drive vehicles, make sure the trans-
fer case is not in NEUTRAL. Always, block
or chock the trailer wheels.
• GCWR must not be exceeded.
• Total weight must be distributed be-
tween 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.
271