FCA Customer Care
Join Date: Jan 2012
Location: MOPAR World Headquarters
From the 2014 Grand Cherokee Owner Manual:
The Malfunction Indicator Light (MIL) is part of
an onboard diagnostic system called OBD II that
monitors engine and automatic transmission control
systems. The light will illuminate when the key is in
the ON/RUN position before engine start. If the bulb
does not come on when turning the key from OFF to
ON/RUN, have the condition checked promptly.
Certain conditions, poor fuel quality, etc., may illuminate
the light after engine start. The vehicle should be serviced
if the light stays on through several of your typical
driving cycles. In most situations, the vehicle will drive
normally and will not require towing.
Prolonged driving with the Malfunction Indicator
Light (MIL) on could cause damage to the engine
control system. It also could affect fuel economy and
drivability. If the MIL is flashing, severe catalytic
converter damage and power loss will soon occur.
Immediate service is required.
A malfunctioning catalytic converter, as referenced
above, can reach higher temperatures than in normal
operating conditions. This can cause a fire if you
drive slowly or park over flammable substances such
as dry plants, wood, cardboard, etc. This could result
in death or serious injury to the driver, occupants or