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Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-13336155) - 2020 - CRC - 5/6/19
Driving and Operating
19
two minutes. For this method to
work properly there must be no
throttle or brake pedal faults.
The engine idle speed will return to
normal once the following conditions
are met:
.
Engine coolant temperature
reaches 65 °C (150 °F).
.
Air intake temperature reaches
0 °C (32 °F).
The high idle speed will be
temporarily interrupted and the
engine speed will return to normal if
any of the following conditions
occur:
.
The brake pedal is applied.
.
The accelerator pedal is
pressed.
.
The transmission is shifted out
of P (Park) or N (Neutral).
.
Vehicle speed is detected.
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 (Vans Only)
The vehicle may have this system
which 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).
On vans, when fast idle is active, a
FAST IDLE ON message will be
displayed in the DIC.
Winter Cover
Pickups
Do not use a winter cover on
pickups.
Vans
If equipped, the winter cover can be
used to enhance heater
performance in extremely cold
conditions below
−
18 °C (0 °F). The
winter cover installs over the grille
and restricts airflow to the engine
compartment.