Winter Cover - Chevrolet GMC Duramax 2023 Manual

Once these inputs are removed, the engine
idle speed will slowly ramp back up to high
idle after the normal delay, if the conditions
for engine coolant temperature and air
intake temperature are still met.
Fast Idle Control
If equipped, this system can be used to
increase the engine idle speed.
Fast Idle control will be enabled when the
following conditions are met:
The parking brake is set.
The transmission is in P (Park) or
N (Neutral).
The vehicle speed is about
0 km/h (0 mph).
The cruise control Set switch is pressed
and released for Preset Fast Idle Speed
(1200 rpm).
Fast Idle control will be disabled when one
or more of the following conditions occur:
The cruise control Set switch is pressed
and released. See Cruise Control in the
owner s manual.
The cruise control Cancel switch is
pressed.
The brake pedal is pressed.
The transmission is shifted out of P (Park)
or N (Neutral).
The parking brake is released.
The vehicle speed is not 0 km/h (0 mph).

Winter Cover

If equipped, the winter cover should be used
to enhance heater performance in cold
conditions below -5 °C (23 °F). The winter
cover installs over the grille and restricts
airflow to the engine compartment.
For vehicles that did not come with a winter
cover, a GM winter cover can be purchased.
See your dealer for additional information.
When the winter cover is in use, the heater,
ventilation, and air conditioning AUTO mode
may not function properly. Use the manual
settings for comfort.
Usage Guidelines
The winter cover should only be used while
operating the vehicle in cold temperatures
or in heavy snow. In these temperatures,
the vehicle does not need a large amount of
air to properly cool the engine. When more
airflow is required to cool the vehicle, the
winter cover should not be used. The
Driving and Operating
following usage guidelines will allow
adequate airflow for proper radiator and air
cooler performance:
Do not use the winter cover if towing a
trailer in conditions above 0 °C (32 °F). The
vehicle may overheat if the radiator is
covered while towing.
Do not use the winter cover if a snow
plow is mounted on the truck.
Do not cover the opening in the front
bumper.
Do not modify the cover. The winter
cover does not cover some sections of the
front of the vehicle to provide enough
airflow.
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