2009 JEEP GRAND CHEROKEE sensor

Manual Compass Calibration
If the compass appears erratic and the “CAL” indicator
does not appear in the EVIC display, you must put the
compass into the Calibration Mode manually, as follows:
1. Turn on the ignition switch.
2. Press the MENU button until Personal Settings (Cus-
tomer Programmable Features) menu is reached.
3. Press the SCROLL button until “Calibrate Compass” is
displayed in the EVIC.
4. Press and release the FUNCTION SELECT button to
start the calibration. The “CAL” indicator will be dis-
played in the EVIC.
5. Complete one or more 360–degree turns (in an area
free from large metal or metallic objects) until the “CAL”
indicator turns off. The compass will now function
normally.
Compass Variance
Compass Variance is the difference between magnetic
North and Geographic North. In some areas of the
country, the difference between magnetic and geographic
North is great enough to cause the compass to give false
readings. For the most accurate compass performance,
the compass variance must be set using the following
procedure:
NOTE:Magnetic materials should be kept away from
the Overhead console. This is where the compass sensor
is located.
UNDERSTANDING YOUR INSTRUMENT PANEL 201
4

respectively. With the temperature setting in these posi-
tions, the system does not attempt automatic comfort
control.
Air Conditioning
The air conditioning in this system is automatic.
Pressing this button while in AUTO mode will
cause the LED to flash three times and remain off.
This indicates that the system is in AUTO and requesting
the air conditioning is not necessary.
Recirculation
The system will automatically control recircu-
lation. However, pressing this button will tem-
porarily put the system in “Recirculation”
mode. This can be used when outside condi-
tions such as smoke, odors, dust, or high humidity are
present. This will cause the LED to illuminate.NOTE:
•The surface of the climate control panel, and the top
center of the instrument panel should be kept free of
debris due to the climate control sensor’s location.
Mud on the windshield may also cause poor operation
of this system.
•To provide you with maximum comfort in the auto-
matic mode, during cold start-ups the blower fan will
remain off until the engine warms up. However, the
fan will engage immediately if the defrost mode is
selected or if you manually select a blower speed.
•Under certain conditions (after the vehicle is turned
off) the climate control system may recalibrate and a
noise may be heard for 20 seconds. This is part of
normal operation.
266 UNDERSTANDING YOUR INSTRUMENT PANEL

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.
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. Only a safe, attentive, and skillful
driver can prevent accidents. The capabilities of an
ERM-equipped vehicle must never be exploited in a
reckless or dangerous manner which could jeopar-
dize the user’s safety or the safety of others.
ESP (Electronic Stability Program)
This system enhances directional control and stability of
the vehicle under various driving conditions. ESP cor-
rects for oversteering or understeering of the vehicle by
applying the brake of the appropriate wheel to assist in
counteracting the oversteer or understeer condition. En-
gine 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.
STARTING AND OPERATING 315
5

WARNING!
With the ESP switched off, the enhanced vehicle
stability offered by ESP and ERM are unavailable. In
an emergency evasive maneuver, the ESP and ERM
systems will not engage to assist in maintaining
stability. The “Full Off” mode is intended for off-
road use only.
TSC (Trailer Sway Control)
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 andfollow the trailer tongue weight recommendations. Refer
to “Trailer Towing” in Section 5 of this manual. 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.
HSA (Hill Start Assist) (4WD Models With NV245
Two–Speed Transfer Case Only)
The HSA system is designed to assist the driver when
starting a vehicle from a stop on a hill. HSA will maintain
the level of brake pressure the driver applied for a short
320 STARTING AND OPERATING

For example, your vehicle has a recommended cold
(parked for more than three hours) tire pressure of 33 psi
(227 kPa). If the ambient temperature is 68°F (20°C) and
the measured tire pressure is 28 psi (193 kPa), a tempera-
ture drop to 20°F (-7°C) will decrease the tire pressure to
approximately 24 psi (165 kPa). This tire pressure is
sufficiently low enough to turn ON the Tire Pressure
Monitoring Telltale Light. Driving the vehicle may cause
the tire pressure to rise to approximately 28 psi (193 kPa),
but the Tire Pressure Monitoring Telltale Light will still
be ON. In this situation, the Tire Pressure Monitoring
Telltale Light will turn OFF only after the tires have been
inflated to the vehicle’s recommended cold tire pressure
value.CAUTION!
•The TPMS has been optimized for the original
equipment tires and wheels. TPMS pressures have
been established for the tire size equipped on your
vehicle. Undesirable system operation or sensor
damage may result when using replacement
equipment that is not of the same size, type, and/or
style. Aftermarket wheels can cause sensor dam-
age. Do not use aftermarket tire sealants or balance
beads if your vehicle is equipped with a TPMS, as
damage to the sensors may result.
•After inspecting or adjusting the tire pressure
always reinstall the valve stem cap. This will
prevent moisture and dirt from entering the valve
stem, which could damage the Tire Pressure Moni-
toring Sensor.
346 STARTING AND OPERATING

NOTE:
•The TPMS is not intended to replace normal tire care
and maintenance, or to provide warning of a tire
failure or condition.
•The TPMS should not be used as a tire pressure gauge
while adjusting your tire pressure.
•Driving on a significantly under-inflated tire causes
the tire to overheat and can lead to tire failure.
Under-inflation also reduces fuel efficiency and tire
tread life, and may affect the vehicle’s handling and
stopping ability.
•The TPMS is not a substitute for proper tire mainte-
nance, and it is the driver ’s responsibility to maintain
correct tire pressure using an accurate tire gauge, even
if under-inflation has not reached the level to trigger
illumination of the Tire Pressure Monitoring Telltale
Light.
•Seasonal temperature changes will affect tire pressure,
and the TPMS will monitor the actual tire pressure in
the tire.
Base System
The Tire Pressure Monitor System (TPMS) uses wireless
technology with wheel rim-mounted electronic sensors to
monitor tire pressure levels. Sensors, mounted to each
wheel as part of the valve stem, transmit tire pressure
readings to the Receiver Module.
NOTE:It is particularly important, for you to regularly
check the tire pressure in all of your tires, and to maintain
the proper pressure.
The TPMS consists of the following components:
•Receiver Module
•Four Tire Pressure Monitoring Sensors
•Tire Pressure Monitoring Telltale Light
STARTING AND OPERATING 347
5

A tire pressure monitoring sensor is located in the spare
wheel, if the vehicle is equipped with a matching full-size
spare wheel and tire assembly. The matching full-size
spare tire can be used in place of any of the four road
tires. A low spare tire will not cause the Tire Pressure
Monitoring Telltale Light to illuminate, a warning mes-
sage to appear, or the chime to sound.
The Tire Pressure Monitoring Telltale Light will
illuminate in the instrument cluster, a “TIRE LOW
PRESSURE” message will display in the instru-
ment cluster for 60 seconds, and an audible chime will be
activated, when one or more of the four active road tire
pressures are low. Should this occur, you should stop as
soon as possible, check the inflation pressure of each tire
on your vehicle, and inflate each tire to the vehicle’s
recommended cold placard pressure value. The system
will automatically update and the Tire Pressure Monitor-
ing Telltale Light will extinguish, once the updated tirepressures have been received. The vehicle may need to be
driven for up to 20 minutes above 15 mph (24 km/h) to
receive this information.
The Tire Pressure Monitoring Telltale Light will flash on
and off for 75 seconds, and remain on solid when a
system fault is detected. In addition, a “CHECK TPM
SYSTEM” message will be displayed for 75 seconds when
a system fault is detected, and a chime will sound. If the
ignition key is cycled, this sequence will repeat, provid-
ing the system fault still exists. The Tire Pressure Moni-
toring Telltale Light will turn off when the fault condition
no longer exists. A system fault can occur by any of the
following:
1. Jamming due to electronic devices or driving next to
facilities emitting the same Radio Frequencies as the TPM
sensors.
2. Installing some form of aftermarket window tinting
that affects radio wave signals.
348 STARTING AND OPERATING

3. Lots of snow or ice around the wheels or wheel
housings.
4. Using tire chains on the vehicle.
5. Using wheels/tires not equipped with TPM sensors.
NOTE:
•If your vehicle is equipped with a matching full-size
spare wheel and tire assembly, it has a tire pressure
monitoring sensor, and can be monitored by the Tire
Pressure Monitoring System (TPMS). In the event that
the matching full-size spare tire is swapped with a low
pressure road tire, the next ignition key cycle will still
show the Tire Pressure Monitoring Telltale Light to be
ON, a “TIRE LOW PRESSURE” message will be
displayed in the instrument cluster for 60 seconds, and
a chime to sound. Driving the vehicle for up to
20 minutes above 15 mph (24 km/h) will turn OFF theTire Pressure Monitoring Telltale Light as long as none
of the road tires are below the low pressure warning
threshold.
•If your vehicle is not equipped with a matching
full-size spare wheel and tire assembly, it does not
have a tire pressure monitoring sensor in the spare tire.
The TPMS will not be able to monitor the tire pressure.
If you install the spare tire, in place of a road tire, that
has a pressure below the low-pressure warning limit,
upon the next ignition key cycle, a chime will sound, a
“TIRE LOW PRESSURE” message will be displayed in
the instrument cluster for 60 seconds, and the Tire
Pressure Monitoring Telltale Light will turn ON. After
driving the vehicle for up to 20 minutes above 15 mph
(25 km/h), the Tire Pressure Monitoring Telltale Light
will flash on and off for 75 seconds and then remain on
solid. In addition, a “CHECK TPM SYSTEM” message
will be displayed for 75 seconds. For each subsequent
ignition key cycle, a chime will sound, a “CHECK
STARTING AND OPERATING 349
5