ignition JEEP GRAND CHEROKEE LIMITED 2019 Service Manual

If the ABS light does not turn on when the ignition is
placed in the ON/RUN or ACC/ON/RUN position, have
the brake system inspected by an authorized dealer.

EMISSIONS INSPECTION AND MAINTENANCE
PROGRAMS
In some localities, it may be a legal requirement to pass an
inspection of your vehicle’s emissions control system.
Failure to pass could prevent vehicle registration.For states that require an Inspection and Main-
tenance (I/M), this check verifies the “Malfunc-
tion Indicator Light (MIL)” is functioning and is
not on when the engine is running, and that the
OBD II system is ready for testing.
Normally, the OBD II system will be ready. The OBD II
system may notbe ready if your vehicle was recently
serviced, recently had a dead battery or a battery replace-
ment. If the OBD II system should be determined not ready
for the I/M test, your vehicle may fail the test.
Your vehicle has a simple ignition actuated test, which you
can use prior to going to the test station. To check if your
vehicle’s OBD II system is ready, you must do the follow-
ing:
1. Cycle the ignition switch to the ON position, but do not crank or start the engine. NOTE:
If you crank or start the engine, you will have to
start this test over.
2. As soon as you cycle the ignition switch to the ON position, you will see the “Malfunction Indicator Light
(MIL)” symbol come on as part of a normal bulb check.
3. Approximately 15 seconds later, one of two things will happen:
• The MIL will flash for about ten seconds and then return
to being fully illuminated until you turn OFF the igni-
tion or start the engine. This means that your vehicle’s
OBD II system is not readyand you should notproceed
to the I/M station.
• The MIL will not flash at all and will remain fully
illuminated until you place the ignition in the off posi-
tion or start the engine. This means that your vehicle’s
OBD II system is readyand you can proceed to the I/M
station.
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GETTING TO KNOW YOUR INSTRUMENT PANEL 163

WARNING!(Continued)
•The capabilities of an ABS equipped vehicle must
never be exploited in a reckless or dangerous manner
that could jeopardize the user ’s safety or the safety of
others.
ABS is designed to function with the OEM tires. Modifica-
tion may result in degraded ABS performance.
Anti-Lock Brake Warning Light
The yellow “Anti-Lock Brake Warning Light” will turn on
when the ignition is turned to the ON/RUN mode and
may stay on for as long as four seconds.
If the “Anti-Lock Brake Warning Light” remains on or
comes on while driving, it indicates that the anti-lock
portion of the brake system is not functioning and that
service is required. However, the conventional brake sys-
tem will continue to operate normally if the “Anti-Lock
Brake Warning Light” is on.
If the “Anti-Lock Brake Warning Light” is on, the brake
system should be serviced as soon as possible to restore the
benefits of anti-lock brakes. If the “Anti-Lock Brake Warn-
ing Light” does not come on when the ignition is turned to
the ON/RUN mode, have the light repaired as soon as
possible.
Electronic Brake Control System
Your vehicle is equipped with an advanced Electronic
Brake Control system (EBC). This system includes Elec-
tronic Brake Force Distribution (EBD), Anti-Lock Brake
System (ABS), Brake Assist System (BAS), Hill Start Assist
(HSA), Traction Control System (TCS), Electronic Stability
Control (ESC), and Electronic Roll Mitigation (ERM). These
systems work together to enhance both vehicle stability
and control in various driving conditions.
Your vehicle may also be equipped with Trailer Sway
Control (TSC), Ready Alert Braking (RAB), Rain Brake
Support (RBS), Dynamic Steering Torque (DST), Hill De-
scent Control (HDC), and Selec-Speed Control (SSC).
Electronic Brake Force Distribution (EBD)
This function manages the distribution of the braking
torque between the front and rear axles by limiting braking
pressure to the rear axle. This is done to prevent overslip of
the rear wheels to avoid vehicle instability, and to prevent
the rear axle from entering ABS before the front axle.
Brake System Warning Light
The red “Brake System Warning Light” will turn on when
the ignition is turned to the ON/RUN mode and may stay
on for as long as four seconds.
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SAFETY 167

If the “Brake System Warning Light” remains on or comes
on while driving, it indicates that the brake system is not
functioning properly and that immediate service is re-
quired. If the “Brake System Warning Light” does not come
on when the ignition is turned to the ON/RUN mode, have
the light repaired as soon as possible.
Brake Assist System (BAS)
The BAS is designed to optimize the vehicle’s braking
capability during emergency braking maneuvers. The sys-
tem detects an emergency braking situation by sensing 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 the benefit of
the system, you must apply continuous braking 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.

For vehicles not equipped with an instrument cluster
display, perform the following steps:
1. Center the steering wheel (front wheels pointingstraight forward).
2. Shift the transmission into PARK.
3. Apply the parking brake.
4. Start the engine.
5. Rotate the steering wheel slightly more than one-half turn to the left.
6. Push the “ESC Off” button located in the lower switch bank below the climate control four times within 20
seconds. The “ESC Off Indicator Light” should turn on
and turn off two times.
7. Rotate the steering wheel back to center and then an additional slightly more than one-half turn to the right.
8. Turn the ignition to the OFF mode and then back to ON. If the sequence was completed properly, the “ESC Off
Indicator Light” will blink several times to confirm HSA
is disabled. 9. Repeat these steps if you want to return this feature to
its previous setting.
Towing With HSA
HSA will also provide assistance to mitigate roll back while
towing a trailer.

NOTE:
•The “ESC Activation/Malfunction Indicator Light” and
the “ESC OFF Indicator Light” come on momentarily
each time the ignition is turned ON.
• Each time the ignition is turned ON, the ESC system will
be on even if it was turned off previously.
• The ESC system will make buzzing or clicking sounds
when it is active. This is normal; the sounds will stop
when ESC becomes inactive following the maneuver
that caused the ESC activation.
The “ESC OFF Indicator Light” indicates the
customer has elected to have the Electronic Sta-
bility Control (ESC) in a reduced mode.
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’s speed are
sufficient to potentially cause wheel lift, it then applies the
appropriate brake and may also reduce engine power to
lessen the chance that wheel lift will occur. 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.
NOTE:
ERM is disabled anytime the ESC is in “Full Off”
mode (if equipped). Refer to “Electronic Stability Control
(ESC)” in this section for a complete explanation of the
available ESC modes.

NOTE:
•The minimum speed for FCW activation is 1 mph
(2 km/h).
• The FCW alerts may be triggered on objects other than
vehicles such as guard rails or sign posts based on the
course prediction. This is expected and is a part of
normal FCW activation and functionality.
• It is unsafe to test the FCW system. To prevent such
misuse of the system, after four Active Braking events
within an ignition cycle, the Active Braking portion of
FCW will be deactivated until the next ignition cycle.
• The FCW system is intended for on-road use only. If the
vehicle is taken off-road, the FCW system should be
deactivated to prevent unnecessary warnings to the
surroundings. If the vehicle enters 4WD Low Range or
ESC Full-Off Mode is active, the FCW system will be
automatically deactivated.

latter is at a farther distance thanMediumsetting. This
provides the most reaction time to avoid a possible colli-
sion.
Changing the FCW status to the “Near” setting, allows the
system to warn the driver of a possible collision with the
vehicle in front when the distance between the vehicle in
the front is much closer. This setting provides less reaction
time than the “Far” and “Medium” settings, which allows
for a more dynamic driving experience.
NOTE:
• Changing the FCW status to “Only Warning” prevents
the system from providing limited active braking, or
additional brake support if the driver is not braking
adequately in the event of a potential frontal collision,
but maintains the audible and visual warnings.
• Changing the FCW status to “Off” prevents the system
from providing autonomous braking, or additional
brake support if the driver is not braking adequately in
the event of a potential frontal collision.
• The system will retain the last setting selected by the
driver after ignition shut down. •
FCW may not react to irrelevant objects such as over-
head objects, ground reflections, objects not in the path
of the vehicle, stationary objects that are far away,
oncoming traffic, or leading vehicles with the same or
higher rate of speed.
• FCW will be disabled like ACC, with the unavailable
screens.
FCW Limited Warning
If the instrument cluster displays “ACC/FCW Limited
Functionality” or “ACC/FCW Limited Functionality Clean
Front Windshield” momentarily, there may be a condition
that limits FCW functionality. Although the vehicle is still
drivable under normal conditions, the active braking may
not be fully available. Once the condition that limited the
system performance is no longer present, the system will
return to its full performance state. If the problem persists,
see your authorized dealer.
Service FCW Warning
If the system turns off, and the instrument cluster displays:
•ACC/FCW Unavailable Service Required
• Cruise/FCW Unavailable Service Required
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SAFETY 191

NOTE:When filling warm tires, the tire pressure may need
to be increased up to an additional 4 psi (28 kPa) above the
recommended cold placard pressure in order to turn the
TPMS Warning Light off.
The system will automatically update, the graphic display
of the pressure value(s) will return to its original color and
the TPMS Warning Light will extinguish once the updated
tire pressure(s) 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.
Service TPM System Warning
The Tire Pressure Monitoring System Warning Light will
flash on and off for 75 seconds, and remain on solid when
a system fault is detected. The system fault will also sound
a chime. The instrument cluster display will display a
“SERVICE TPM SYSTEM” message for a minimum of five
seconds. This message is then followed by a graphic
display, with “- -“ in place of the pressure value(s),
indicating which Tire Pressure Monitoring Sensor(s) is not
being received. If the ignition switch is cycled, this sequence will repeat,
providing the system fault still exists. If the system fault no
longer exists, the Tire Pressure Monitoring System Warning
Light will no longer flash, the
SERVICE TPM SYSTEM
message will not be present, and a pressure value will be
displayed instead of dashes. A system fault can occur by
any of the following:
• Jamming due to electronic devices or driving next to
facilities emitting the same Radio Frequencies as the
TPM sensors.
• Lots of snow or ice around the wheels or wheel hous-
ings.
• Using tire chains on the vehicle.
• Using wheels/tires not equipped with TPM sensors.
196 SAFETY

NOTE:There is no 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 switch cycle, the Tire Pressure
Monitoring System Warning Light will remain on, a chime
will sound, and the instrument cluster display will still
display a pressure value in the different color graphic
display and an “Inflate to XX” message will be displayed.
After driving the vehicle for up to 20 minutes above
15 mph (24 km/h), the Tire Pressure Monitoring System
Warning Light will flash on and off for 75 seconds and then
remain on solid. In addition, the instrument cluster display
will display a “SERVICE TPM SYSTEM message for five
seconds and then display dashes (- -) in place of the
pressure value. For each subsequent ignition switch cycle,
a chime will sound, the Tire Pressure Monitoring System
Warning Light will flash on and off for 75 seconds and then
remain on solid, and the instrument cluster display will
display a SERVICE TPM SYSTEM message for five sec-
onds and then display dashes (- -) in place of the pressure
value. Once you repair or replace the original road tire, and
reinstall it on the vehicle in place of the spare tire, the
TPMS will update automatically. In addition, the Tire Pressure Monitoring System Warning
Light will turn off and the graphic in the instrument cluster
display will display a new pressure value instead of dashes
(- -), 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 (24 km/h) in order for the TPMS to receive this
information.
TPMS Deactivation — If Equipped
The Tire Pressure Monitoring System (TPMS) can be deac-
tivated if replacing all four wheel and tire assemblies (road
tires) with wheel and tire assemblies that do not have
TPMS Sensors, such as when installing winter wheel and
tire assemblies on your vehicle.
To deactivate the TPMS, first, replace all four wheel and
tire assemblies (road tires) with tires not equipped with
Tire Pressure Monitoring (TPM) Sensors. Then, drive the
vehicle for 20 minutes above 15 mph (24 km/h). The TPMS
will chime, the TPMS Warning Light will flash on and off
for 75 seconds and then remain on. The instrument cluster
will display the “SERVICE TPM SYSTEM” message and
then display dashes (--) in place of the pressure values.
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SAFETY 197