2018 JEEP GRAND CHEROKEE LIMITED Service and maintenance

WARNING!(Continued)
vehicle control could occur that may result in an
accident involving serious injury or death.
• Access, or allow others to access, information
stored in your vehicle systems, including personal
information.
For further information, refer to “Cybersecurity” in “Mul-
timedia”.
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.
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GETTING TO KNOW YOUR INSTRUMENT PANEL 161

WARNING!
You can be badly injured working on or around a
motor vehicle. Only do service work for which you
have the knowledge and the proper equipment. If you
have any doubt about your ability to perform a service
job, take your vehicle to a competent mechanic.
Engine Oil
Change Engine Oil — Gasoline Engine
Refer to “Scheduled Servicing” in this section for the
proper maintenance intervals.
NOTE:Under no circumstances should oil change inter-
vals exceed 10,000 miles (16,000 km), 12 months or 350
hours of engine run time, whichever comes first. The 350
hours of engine run or idle time is generally only a concern
for fleet customers.
Gasoline Engine Oil Selection
For best performance and maximum protection under all
types of operating conditions, the manufacturer only rec-
ommends engine oils that are API Certified and meet the
requirements of FCA Material Standard MS-6395.
American Petroleum Institute (API) Engine Oil
Identification Symbol
This symbol means that the oil has
been certified by the American Pe-
troleum Institute (API). The manu-
facturer only recommends API Cer-
tified engine oils.
This symbol certifies 0W-20, 5W-20,
0W-30, 5W-30 and 10W-30 engine
oils.
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SERVICING AND MAINTENANCE 443

environment. Contact an authorized dealer, service station
or governmental agency for advice on how and where used
oil and oil filters can be safely discarded in your area.
Engine Oil Filter
The engine oil filter should be replaced with a new filter at
every engine oil change.
Engine Oil Filter Selection
This manufacturer’s engines have a full-flow type dispos-
able oil filter. Use a filter of this type for replacement. The
quality of replacement filters varies considerably. Only
high quality filters should be used to assure most efficient
service. Mopar engine oil filters are high quality oil filters
and are recommended.
Engine Air Cleaner Filter
Refer to the “Maintenance Plan” in this section for the
proper maintenance intervals.
NOTE:Be sure to follow the “Severe Duty Conditions”
maintenance interval if applicable.

Under normal operating conditions, the catalytic converter
will not require maintenance. However, it is important to
keep the engine properly tuned to assure proper catalyst
operation and prevent possible catalyst damage.
NOTE:Intentional tampering with emissions control sys-
tems can result in civil penalties being assessed against
you.
In unusual situations involving grossly malfunctioning
engine operation, a scorching odor may suggest severe and
abnormal catalyst overheating. If this occurs, stop the
vehicle, turn off the engine and allow it to cool. Service,
including a tune-up to manufacturer’s specifications,
should be obtained immediately.
To minimize the possibility of catalytic converter damage:
• Do not interrupt the ignition when the transmission is in
gear and the vehicle is in motion.
• Do not try to start the vehicle by pushing or towing the
vehicle.
• Do not idle the engine with any ignition components
disconnected or removed, such as when diagnostic
testing, or for prolonged periods during very rough idle
or malfunctioning operating conditions.Cooling System

Tread Wear Indicators
Tread wear indicators are in the original equipment tires to
help you in determining when your tires should be re-
placed.
These indicators are molded into the bottom of the tread
grooves. They will appear as bands when the tread depth
becomes a 1/16 of an inch (1.6 mm). When the tread isworn to the tread wear indicators, the tire should be
replaced. Refer to “Replacement Tires” in this section for
further information.
Life Of Tire
The service life of a tire is dependent upon varying factors
including, but not limited to:
•
Driving style.
• Tire pressure - Improper cold tire inflation pressures can
cause uneven wear patterns to develop across the tire
tread. These abnormal wear patterns will reduce tread
life, resulting in the need for earlier tire replacement.
• Distance driven.
• Performance tires, tires with a speed rating of V or
higher, and Summer tires typically have a reduced tread
life. Rotation of these tires per the vehicle scheduled
maintenance is highly recommended.