Lincoln 2014 MKZ Hybrid Owner's Manual page 157

Frequently asked questions
Question
What are the series of clicks from the cargo
area when I first turn the key in the ignition?
Why does the engine sometimes start at
key-on?
Why does it take a long time before the
engine shuts down?
Why does my engine never shut down
above 85 mph (137 km/h)?
Why does my engine stay on when it is
extremely cold outside?
MKZ (CC9)
Unique Driving Characteristics
The high voltage battery is electrically
isolated from the rest of the vehicle when
the key is off. When you turn the key to on,
high voltage contactors inside the battery
are closed to make the electricity available
to the motor/generator and enable the
vehicle to drive. The clicks are the sound
of these contactors as they close and open
during start up and shut down.
The vehicle's computer will determine if an
engine start is required at key-on. Silent
key start will start the engine if it is neces-
sary for cabin heating, windshield defrost,
or if the outside temperature is low.
There are several reasons the engine stays
on for an extended amount of time when
you first start it. One common reason is to
ensure that the emissions components are
warm enough to minimize tailpipe emis-
sions. As the climate gets cooler, this
engine-on time is extended.
The engine is required to turn on above
this speed to protect the transmission
hardware.
In order to ensure that the climate control
system can begin heating the cabin or
defrosting the windshield as soon as a
driver requests it, the engine coolant
temperature has to be kept sufficiently hot.
Keeping the engine on is required to
maintain the correct minimum temperature.
155
Answer