Jeep Grand Cherokee 2013 Operating Information Manual page 316

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 emis-
sions, engine, and automatic transmission con-
trol systems. When these systems are operat-
ing 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 diagnos-
tic codes and other information to assist your
service technician in making repairs. Although
your vehicle will usually be drivable and not
need towing, see your authorized dealer for
service as soon as possible.
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CAUTION!
• Prolonged driving with the MIL on could
cause further damage to the emission con-
trol system. It could also affect fuel economy
and drivability. The vehicle must be serviced
before any emissions tests can be per-
formed.
• If the MIL is flashing, while the engine is
running, severe catalytic converter dam-
age and power loss will soon occur. Imme-
diate service is required.
Loose Fuel Filler Cap Message
If the vehicle diagnostic system de-
termines that the fuel filler cap is
loose, improperly installed, or dam-
aged, a loose gascap indicator will
display in the EVIC telltale display
area. Refer to "Electronic Vehicle
Information Center (EVIC) in "Understanding
Your Instrument Panel" for further information.
Tighten the fuel filler cap properly and press the
SELECT button to turn off the message. If the
problem continues, the message will appear the
next time the vehicle is started.
A loose, improperly installed, or damaged fuel
filler cap may also turn on the Malfunction
Indicator Light (MIL).
REPLACEMENT PARTS
Use of genuine MOPAR® parts for normal/
scheduled maintenance and repairs is highly
recommended to ensure the designed perfor-
mance. Damage or failures caused by the use
of non-MOPAR® parts for maintenance and
repairs will not be covered by the manufactur-
er's warranty.
MAINTENANCE PROCEDURES
The pages that follow contain the required
maintenance services determined by the engi-
neers who designed your vehicle.
Besides those maintenance items specified in
the fixed maintenance schedule, there are other
components which may require servicing or
replacement in the future.