2018 JEEP GRAND CHEROKEE Emissions

ONBOARD DIAGNOSTIC
SYSTEM — OBD II
Your vehicle is equipped with a sophisticated
Onboard Diagnostic system called OBD II.
This system monitors the performance of the
emissions, engine, and transmission control
systems. When these systems are operating
properly, your vehicle will provide excellent
performance and fuel economy, as well as
engine emissions well within current govern-
ment regulations.
If any of these systems require service, the
OBD II system will turn on the Malfunction
Indicator Light (MIL). It will also store diag-
nostic codes and other information to assist
your service technician in making repairs.
Although your vehicle will usually be drivable
and not need towing, see an authorized
dealer for service as soon as possible.
CAUTION!
• Prolonged driving with the MIL on could
cause further damage to the emission
control system. It could also affect fuel
economy and driveability. The vehicle
must be serviced before any emissions
tests can be performed.
• If the MIL is flashing while the vehicle is
running, severe catalytic converter dam-
age and power loss will soon occur. Im-
mediate service is required.
Onboard Diagnostic System (OBD II)
Cybersecurity
Your vehicle is required to have an Onboard
Diagnostic system (OBD II) and a connection
port to allow access to information related to
the performance of your emissions controls.
Authorized service technicians may need to
access this information to assist with the
diagnosis and service of your vehicle and
emissions system.
WARNING!
• ONLY an authorized service technician
should connect equipment to the OBD II
connection port in order to diagnose or
service your vehicle.
• If unauthorized equipment is connected
to the OBD II connection port, such as a
driver-behavior tracking device, it may:
• Be possible that vehicle systems,
including safety related systems,
could be impaired or a loss of ve-
hicle control could occur that may
result in an accident involving seri-
ous injury or death.
• Access, or allow others to access,
information stored in your vehicle
systems, including personal infor-
mation.
For further information, refer to “Cybersecu-
rity” in “Multimedia”.
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WARNING!
• Never have any smoking materials lit in
or near the vehicle when the fuel door is
open or the tank is being filled.
• Never add fuel when the engine is run-
ning. This is in violation of most coun-
tries regulations and may cause the
“Malfunction Indicator Light” to turn
on.
• A fire may result if fuel is pumped into a
portable container that is inside of a
vehicle. You could be burned. Always
place fuel containers on the ground
while filling.
CAUTION!
To avoid fuel spillage and overfilling, do
not “top off” the fuel tank after filling.
Avoid Using Contaminated Fuel
Fuel that is contaminated by water or dirt can
cause severe damage to the engine fuel sys-
tem. Proper maintenance of the engine fuelfilter and fuel tank is essential. Refer to
“Dealer Service” in “Servicing And Mainte-
nance” in your Owner’s Manual for further
information.
Bulk Fuel Storage — Diesel Fuel
If you store quantities of fuel, good mainte-
nance of the stored fuel is also essential. Fuel
contaminated with water will promote the
growth of “microbes.” These microbes form
“slime” that will clog the fuel filtration sys-
tem and lines. Drain condensation from the
supply tank and change the line filter on a
regular basis.
NOTE:
When a diesel engine is allowed to run out of
fuel, air is pulled into the fuel system.
If the vehicle will not start, refer to “Dealer
Service / Priming If The Engine Has Run Out
Of Fuel” in “Servicing And Maintenance” in
your Owner’s Manual for further information.
WARNING!
Do not open the high pressure fuel system
with the engine running. Engine operation
WARNING!
causes high fuel pressure. High pressure
fuel spray can cause serious injury or
death.
Diesel Exhaust Fluid
Your vehicle is equipped with a Selective
Catalytic Reduction system to meet the very
stringent diesel emissions standards required
by the Environmental Protection Agency.
The purpose of the SCR system is to reduce
levels of NOx (oxides of nitrogen emitted from
engines) that are harmful to our health and
the environment to a near-zero level. A small
quantity of Diesel Exhaust Fluid (DEF) is
injected into the exhaust upstream of a cata-
lyst where, when vaporized, it converts smog-
forming nitrogen oxides (NOx) into harmless
nitrogen (N2) and water vapor (H2O), two
natural components of the air we breathe.
You can operate with the comfort that your
vehicle is contributing to a cleaner, healthier
world environment for this and generations to
come.
181

System Overview
This vehicle is equipped with a Diesel Ex-
haust Fluid (DEF) injection system and a
Selective Catalytic Reduction (SCR) catalyst
to meet the emission requirements.
The DEF injection system consists of the
following components:
• DEF tank
• DEF pump
• DEF injector
• Electronically-heated DEF lines
• NOx sensors
• Temperature sensors
• SCR catalyst
The DEF injection system and SCR catalyst
enable the achievement of diesel emissions
requirements; while maintaining outstanding
fuel economy, drivability, torque and power
ratings.Refer to “Instrument Cluster Display” in
“Getting To Know Your Instrument Panel” for
system messages and warnings.
NOTE:
• Your vehicle is equipped with a DEF injec-
tion system. You may occasionally hear an
audible clicking noise from under the ve-
hicle at a stop. This is normal operation.
• The DEF pump will run for a period of time
after engine shutdown to purge the DEF
system. This is normal operation and may
be audible from the rear of the vehicle.
Diesel Exhaust Fluid Storage
Diesel Exhaust Fluid (DEF) is considered a
very stable product with a long shelf life. If
DEF is kept in temperatures between 10° and
90°F (-12° and 32°C), it will last a minimum
of one year.
DEF is subject to freezing at the lowest tem-
peratures. For example, DEF may freeze at
temperatures at or below 12° F (-11° C). The
system has been designed to operate in this
environment.
NOTE:
When working with DEF, it is important to
know that:
• Any containers or parts that come into con-
tact with DEF must be DEF compatible
(plastic or stainless steel). Copper, brass,
aluminum, iron or non-stainless steel
should be avoided as they are subject to
corrosion by DEF.
• If DEF is spilled, it should be wiped up
completely.
STARTING AND OPERATING
182

Mileage or time passed (which-
ever comes first)
7,500
15,000
22,500
30,000
37,500
45,000
52,500
60,000
67,500
75,000
82,500
90,000
97,500
105,000
112,500
120,000
127,500
135,000
142,500
150,000
Or Months: 12 24 36 48 60 72 84 96 108 120 132 144 156 168 180 192 204 216 228 240
Kilometers or time passed (which-
ever comes first):
12,000
24,000
36,000
48,000
60,000
72,000
84,000
96,000
108,000
120,000
132,000
144,000
156,000
168,000
180,000
192,000
204,000
216,000
228,000
240,000
Inspect or change the transfer
case fluid if using your vehicle
for any of the following: police,
taxi, fleet, or frequent trailer
towing.XX X
Change Transfer Case Fluid. X X
Inspect and replace PCV valve if
necessary.†X
* The spark plug change interval is mileage
based only, yearly intervals do not apply.
** DOT 4 brake fluid is time based only;
mileage intervals do not apply.
† This maintenance is recommended by the
manufacturer to the owner, but is not re-
quired to maintain emissions warranty.WARNING!
• You can be badly injured working on or
around a motor vehicle. Do only service
work for which you have the knowledge
and the right equipment. If you have any
doubt about your ability to perform a
service job, take your vehicle to a com-
petent mechanic.
WARNING!
• Failure to properly inspect and maintain
your vehicle could result in a component
malfunction and effect vehicle handling
and performance. This could cause an
accident.
233

Miles:6,000
12,000
18,000
24,000
30,000
36,000
42,000
48,000
54,000
60,000
66,000
72,000
78,000
84,000
90,000
96,000
102,000
108,000
114,000
120,000
126,000
132,000
138,000
144,000
150,000
Or Months: 6 12 18 24 30 36 42 48 54 60 66 72 78 84 90 96 102 108 114 120 126 132 138 144 150
Or Kilometers:
10,000
20,000
30,000
40,000
50,000
60,000
70,000
80,000
90,000
100,000
110,000
120,000
130,000
140,000
150,000
160,000
170,000
180,000
190,000
200,000
210,000
220,000
230,000
240,000
250,000
Inspect front suspension, tie rod
ends, and boot seals, for cracks or
leaks and all parts for damage,
wear, improper looseness or end
play; replace if necessary.XXXXXXXXXXXX
Replace the engine air cleaner fil-
ter.XXXXX
Replace the air conditioning filter. X X X X X X
Inspect and replace the PCV Valve
if necessary. †X
Replace the spark plugs 6.4L En-
gine. (**)XX
Replace the spark plugs 6.2L En-
gine. (**)XXX X
Flush and replace the engine cool-
ant at 120 months if not done at
150,000 miles (240,000 km).XX
(*) The brake fluid change interval is time
based only, Mileage intervals do not apply.(**) The spark plug change interval is mile-
age based only, Monthly intervals do not ap-
ply.† This maintenance is recommended by the
manufacturer to the owner, but is not re-
quired to maintain emissions warranty.
237

voir, take some washer fluid and apply it to a
cloth or towel and wipe clean the wiper
blades, this will help blade performance. To
prevent freeze-up of your windshield washer
system in cold weather, select a solution or
mixture that meets or exceeds the tempera-
ture range of your climate. This rating infor-
mation can be found on most washer fluid
containers.
WARNING!
Commercially available windshield washer
solvents are flammable. They could ignite
and burn you. Care must be exercised
when filling or working around the washer
solution.
Maintenance-Free Battery
Your vehicle is equipped with a maintenance-
free battery. You will never have to add water,
nor is periodic maintenance required.
WARNING!
• Battery fluid is a corrosive acid solution
and can burn or even blind you. Do not
WARNING!
allow battery fluid to contact your eyes,
skin, or clothing. Do not lean over a
battery when attaching clamps. If acid
splashes in eyes or on skin, flush the
area immediately with large amounts of
water. Refer to “Jump Starting Proce-
dure” in “In Case Of Emergency” for
further information.
• Battery gas is flammable and explosive.
Keep flame or sparks away from the
battery. Do not use a booster battery or
any other booster source with an output
greater than 12 Volts. Do not allow cable
clamps to touch each other.
• Battery posts, terminals, and related ac-
cessories contain lead and lead com-
pounds. Wash hands after handling.
CAUTION!
• It is essential when replacing the cables
on the battery that the positive cable is
attached to the positive post and the
negative cable is attached to the nega-
tive post. Battery posts are marked posi-
CAUTION!
tive (+) and negative (-) and are identi-
fied on the battery case. Cable clamps
should be tight on the terminal posts
and free of corrosion.
• If a “fast charger” is used while the
battery is in the vehicle, disconnect both
vehicle battery cables before connecting
the charger to the battery. Do not use a
“fast charger” to provide starting volt-
age.
DEALER SERVICE
An authorized dealer has the qualified ser-
vice personnel, special tools, and equipment
to perform all service operations in an expert
manner. Service Manuals are available which
include detailed service information for your
vehicle. Refer to these Service Manuals be-
fore attempting any procedure yourself.
NOTE:
Intentional tampering with emissions control
systems may void your warranty and could
result in civil penalties being assessed
against you.
SERVICING AND MAINTENANCE
248

are recommended. Using gasolines that have
these additives may help improve fuel
economy, reduce emissions, and maintain
vehicle performance.
Poor quality gasoline can cause problems
such as hard starting, stalling and stumble. If
you experience these problems, try another
brand of gasoline before considering service
for the vehicle.
5.7L Engine
Theses engines are designed to meet all
emissions regulations and provide satisfac-
tory fuel economy and performance when
using high-quality unleaded gasoline having
an Research Octane Number (RON) of 91 to
95. The manufacturer recommends the use
of a 95 Research Octane Number for opti-
mum performance.
Light spark knock at low engine speeds is not
harmful to your engine. However, continued
heavy spark knock at high speeds can cause
damage, and immediate service is required.
Poor quality gasoline can cause problems
such as hard starting, stalling, and hesita-tions. If you experience these symptoms, try
another brand of gasoline before considering
service for the vehicle.
Besides using unleaded gasoline with the
proper octane rating, gasolines that contain
detergents, corrosion and stability additives
are recommended. Using gasolines that have
these additives may help improve fuel
economy, reduce emissions, and maintain
vehicle performance.
Poor quality gasoline can cause problems
such as hard starting, stalling and stumble. If
you experience these problems, try another
brand of gasoline before considering service
for the vehicle.
6.2L/6.4L Engine
Your vehicle is designed to meet all emissions
regulations and provide excellent fuel
economy and performance when using high-
quality unleaded gasoline having an Re-
search Octane Number (RON) of 98 or
higher. The manufacturer recommends the
use of 98 Research Octane Number (RON) or
higher for optimum performance.Light spark knock at low engine speeds is not
harmful to your engine. However, continued
heavy spark knock at high speeds can cause
damage and immediate service is required.
Poor quality gasoline can cause problems
such as hard starting, stalling, and hesita-
tions. If you experience these symptoms, try
another brand of gasoline before considering
service for the vehicle.
Methanol
(Methyl) is used in a variety of concentrations
when blended with unleaded gasoline. You
may find fuels containing 3% or more metha-
nol along with other alcohols called cosol-
vents. Problems that result from using
methanol/gasoline are not the responsibility
of the manufacturer. While MTBE is an oxy-
genate made from Methanol, it does not have
the negative effects of Methanol.
WARNING!
Do not use gasolines containing Methanol.
Use of these blends may result in starting
and drivability problems and may damage
critical fuel system components.
TECHNICAL SPECIFICATIONS
272

Ethanol
The manufacturer recommends that your ve-
hicle be operated on fuel containing no more
than 15% ethanol. Purchasing your fuel from
a reputable supplier may reduce the risk of
exceeding this 15% limit and/or of receiving
fuel with abnormal properties. It should also
be noted that an increase in fuel consump-
tion should be expected when using ethanol-
blended fuels, due to the lower energy con-
tent of ethanol. Problems that result from
using methanol/gasoline or E-85 ethanol
blends are not the responsibility of the
manufacturer.
CAUTION!
Use of fuel with Ethanol content higher
than 15% may result in engine malfunc-
tion, starting and operating difficulties,
and materials degradation. These adverse
effects could result in permanent damage
to your vehicle.
Reformulated Gasoline
Many areas of the country require the use of
cleaner burning gasoline referred to as “Re-
formulated Gasoline”. Reformulated gasoline
contains oxygenates and are specifically
blended to reduce vehicle emissions and im-
prove air quality.
The use of reformulated gasoline is recom-
mended. Properly blended reformulated
gasoline will provide improved performance
and durability of engine and fuel system
components.
Do Not Use E-85 In Non-Flex Fuel
Vehicles
Non-Flex Fuel Vehicles (FFV) are compatible
with gasoline containing up to 15% ethanol
(E-15). Use of gasoline with higher ethanol
content may void the New Vehicle Limited
Warranty.
If a Non-FFV vehicle is inadvertently fueled
with E-85 fuel, the engine will have some or
all of these symptoms:
• Operate in a lean mode.
• OBD II “Malfunction Indicator Light” on.• Poor engine performance.
• Poor cold start and cold drivability.
• Increased risk for fuel system component
corrosion.
CNG And LP Fuel System Modifications
Modifications that allow the engine to run on
compressed natural gas (CNG) or liquid pro-
pane (LP) may result in damage to the en-
gine, emissions, and fuel system compo-
nents. Problems that result from running
CNG or LP are not the responsibility of the
manufacturer and may void or not be covered
under the New Vehicle Limited Warranty.
Materials Added To Fuel
Indiscriminate use of fuel system cleaning
agents should be avoided. Many of these
materials intended for gum and varnish re-
moval may contain active solvents or similar
ingredients. These can harm fuel system gas-
ket and diaphragm materials.
273