2011 JEEP GRAND CHEROKEE sensor

NOTE:If the ACC “Clean Radar Sensor In Front Of
Vehicle” warning is active Normal (Fixed Speed) Cruise
Control is still available. For additional information refer
to “Normal (Fixed Speed) Cruise Control Mode” in this
section. If weather conditions are not a factor, the driver should
examine the sensor. It may require cleaning or removal of
an obstruction. The sensor is located in the center of the
vehicle behind the lower grille.
To keep the ACC System operating properly, it is impor-
tant to note the following maintenance items:
•Always keep the sensor clean. Carefully wipe the
sensor lens with a soft cloth. Be cautious not to
damage the sensor lens.
•Do not remove any screws from the sensor. Doing so
could cause an ACC system malfunction or failure and
require a sensor realignment.
•If the sensor is damaged due to a collision, see your
authorized dealer for service.
Clean Radar Sensor Warning
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UNDERSTANDING THE FEATURES OF YOUR VEHICLE 181

•Do not attach or install any accessories near the sensor,
including transparent material or aftermarket grilles.
Doing so could cause an ACC system failure or
malfunction.
When the condition that deactivated the system is no
longer present, the system will return to the “Adaptive
Cruise Control Off” state and will resume function by
simply reactivating it.
NOTE:
•If the “Clean Radar Sensor In Front Of Vehicle”
message occurs frequently (e.g. more than once on
every trip) without any snow, rain, mud, or other
obstruction, have the radar sensor realigned at your
authorized dealer.
•Installing a snow plow, front-end protector, an after-
market grille or modifying the grille is not recom-
mended. Doing so may block the sensor and inhibit
ACC operation.
Removing ACC Sensor For Off-Roading
NOTE: When off-roading, it may be advisable to re-
move the ACC sensor. The sensor is located behind the
front lower grille in the center of the vehicle. After
removing the lower fascia, you may remove the lower
sensor and bracket assembly.
To remove the sensor follow these instructions:
1. Unplug the connector by depressing the two tabs on
the connector and pulling it out. Do not pull by the
wiring or use any tools to remove the connector.
2. Remove the wiring christmas tree attachment from the
back of the bracket.
3. Remove the two M6 fasteners that connect the bracket
to the bumper.
182 UNDERSTANDING THE FEATURES OF YOUR VEHICLE

NOTE:Do not change the adjustment fasteners or pull
the sensor off of the bracket. Doing so may misalign the
sensor.
Store the sensor and bracket assembly in a safe location.
The wiring and connector must be stowed properly after
the sensor and bracket assembly is removed.
A connector plug is stowed on top of the bumper beam.
Insert the wiring connector into the connector plug.
NOTE: When the sensor is removed, Adaptive Cruise
Control, Normal Cruise Control, and Forward Collision
Warning will not be available. The cluster will display the
warning “ACC/FCW Unavailable - Service Radar Sen-
sor.” To reinstall the sensor and bracket assembly reverse the
process above. The fastener torque required to assembly
the bracket back to the beam is 6.6 ft lbs (9 Nm).
ACC Unavailable Warning
If the system turns off, and the EVIC displays “ACC/
FCW Unavailable, Vehicle System Error”, there may be a
temporary malfunction that limits ACC functionality.
Although the vehicle is still drivable under normal
conditions, ACC will be temporarily unavailable. If this
occurs, try activating ACC again later, following a key
cycle. If the problem persists, see your authorized dealer.3
UNDERSTANDING THE FEATURES OF YOUR VEHICLE 183

Service ACC Warning
If the system turns off, and the EVIC displays “ACC/
FCW Unavailable Service Radar Sensor”, it indicates
there is an internal system fault. Although the vehicle is
still drivable under normal conditions, have the system
checked by an authorized dealer.
Precautions While Driving With ACC
In certain driving situations, ACC may have detection
issues. In these cases, ACC may brake late or unexpect-
edly. The driver needs to stay alert and may need to
intervene.
Adding A Trailer Hitch
The weight of a trailer/hitch may affect the performance
of ACC. If there is a noticeable change in performance
following the installation of a trailer/hitch, or if the ACC
performance does not return to normal after removing
the trailer/hitch see your authorized dealer.
ACC/FCW Unavailable Warning
184 UNDERSTANDING THE FEATURES OF YOUR VEHICLE

•The Electronic Stability Control/Traction Control Sys-
tem (ESC/TCS) activates.
To Resume
Press the RES+button and then remove your foot from
the accelerator pedal. The EVIC will display the last set
speed.
To Turn Off
The system will turn off and erase the set speed in
memory if:
•You push the ON/OFF button.
•You turn off the ignition.
•You engage Four-Wheel Drive Low.
If the Cruise Control system is turned off and reactivated,
the system will return to the last driver setting (ACC or
Normal Cruise Control).
Forward Collision Warning — If Equipped
Forward Collision Warning (FCW) warns the driver of a
potential collision with the vehicle in front of you and
prompts the driver to take action in order to avoid the
collision.
FCW monitors the information from the forward looking
sensor as well as the Electronic Brake Controller (EBC),
wheel speed sensors, i.e., to calculate a probable rear-end
collision. When the system determines that a rear-end
collision is probable a warning message (both audible
and visual) will be displayed on the EVIC. When the
system determines a collision with the vehicle in front of
you is no longer probable, the warning message will be
deactivated.
190 UNDERSTANDING THE FEATURES OF YOUR VEHICLE

•FCW will not react to irrelevant objects such as over-
head objects, ground reflections, objects not in the path
of the car, stationary objects that are far away, oncom-
ing traffic, or leading vehicles with the same or higher
rate of speed.
•FCW will be disabled like ACC below with the un-
available screens.
FCW Unavailable Warning
If the system turns off, and the EVIC displays “ACC/
FCW Unavailable, Vehicle System Error”, there may be a
temporary malfunction that limits FCW functionality.
Although the vehicle is still drivable under normal
conditions, FCW will be temporarily unavailable. If this
occurs, try activating FCW again later, following a key
cycle. If the problem persists, see your authorized dealer.
Service FCW Warning
If the system turns off, and the EVIC displays “ACC/
FCW Unavailable Service Radar Sensor”, it indicates
there is an internal system fault. Although the vehicle is
still drivable under normal conditions, have the system
checked by an authorized dealer.
ACC/FCW Unavailable Warning
194 UNDERSTANDING THE FEATURES OF YOUR VEHICLE

PARKSENSEREAR PARK ASSIST —
IF EQUIPPED
The ParkSense Rear Park Assist system provides visual
and audible indications of the distance between the rear
fascia and a detected obstacle when backing up, e.g.
during a parking maneuver. Refer to ParkSense System
Usage Precautions for limitations of this system and
recommendations.
ParkSense will retain the last system state (enabled or
disabled) from the last ignition cycle when the ignition is
changed to the ON/RUN position.
ParkSense can be active only when the shift lever is in
REVERSE. If ParkSense is enabled at this shift lever
position, the system will remain active until the vehicle
speed is increased to approximately 11 mph (18 km/h) or
above. The system will become active again if the vehicle
speed is decreased to speeds less than approximately
10 mph (16 km/h).
ParkSense Sensors
The four ParkSense sensors, located in the rear fascia/
bumper, monitor the area behind the vehicle that is
within the sensors’ field of view. The sensors can detect
obstacles from approximately 12 in (30 cm) up to 79 in
(200 cm) from the rear fascia/bumper in the horizontal
direction, depending on the location, type and orienta-
tion of the obstacle.
ParkSense Warning Display
The ParkSense Warning screen will only be displayed if
Sound and Display is selected from the Customer- Pro-
grammable Features section of the Electronic Vehicle
Information Center (EVIC). Refer to “Electronic Vehicle
Information Center (EVIC)/Personal Settings (Customer-
Programmable Features)” in “Understanding Your In-
strument Panel” for further information.
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UNDERSTANDING THE FEATURES OF YOUR VEHICLE 195

Enabling And Disabling ParkSense
ParkSensecan be enabled and disabled with a switch
located in the switch bank of the instrument panel or
through the Customer-Programmable Features section of
the EVIC. The available choices are: OFF, Sound Only, or
Sound and Display. Refer to “Electronic Vehicle Informa-
tion Center (EVIC)/Personal Settings (Customer-Pro-
grammable Features)” in “Understanding Your Instru-
ment Panel” for further information.
When the ParkSense switch is pressed to
disable the system, the instrument cluster will
display the “PARK ASSIST OFF” message for
approximately five seconds. Refer to “Elec-
tronic Vehicle Information Center (EVIC)” in “Under-
standing Your Instrument Panel” for further information.
When the shift lever is moved to REVERSE and the
system is disabled, the EVIC will display the “PARK
ASSIST OFF” message for as long as the vehicle is in
REVERSE. The ParkSense
switch LED will be ON when Park-
Sense is disabled or defective. The ParkSense switch
LED will be OFF when the system is enabled.
The ParkSense system uses four sensors located in the
rear bumper fascia to scan for obstacles up to 79 in
(200 cm) away from the rear bumper fascia. The warning
display located above in the Instrument Cluster ’s EVIC
provides both visual and audible warnings to indicate
the range of the object.
Service The ParkSense Rear Park Assist System
When the ParkSenseRear Park Assist System is mal-
functioning, the instrument cluster will actuate a single
chime, once per ignition cycle, and it will display the
“CLEAN PARK ASSIST SENSORS” or the “SERVICE
PARK ASSIST SYSTEM” message. Refer to “Electronic
Vehicle Information Center (EVIC)” in “Understanding
Your Instrument Panel” for further information. When
the shift lever is moved to REVERSE and the system has
200 UNDERSTANDING THE FEATURES OF YOUR VEHICLE