Engine Heater - GMC CHEVROLET Silverado 6500HD 2019 Owner's Manual

212 Driving and Operating
conditions that can raise idle speed
are low voltage, DPF regeneration,
air conditioning compressor loads,
and engine warmup. These speeds
can range from approximately 600
to 1000 rpm.
Elevated Idle
The engine has a cold temperature
high idle feature which elevates the
engine idle speed from base idle to
1050 to 1100 rpm when outside
temperatures are below 0 °C (32 °F),
and the engine coolant temperature
is below 65 °C (150 °F). This feature
enhances heater performance by
raising the engine coolant
temperature faster.
When the engine is started, it will
slowly ramp up to the high idle
speed after a delay of a few
seconds up to approximately
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.

Engine Heater

The engine heater can provide
easier starting and better fuel
economy during engine warm-up in
cold weather conditions at or below
18 °C (0 °F). Vehicles with an
engine heater should be plugged in
at least four hours before starting.
An internal thermostat in the
plug-end of the cord may exist,
which will prevent engine heater
operation at temperatures above
18 °C (0 °F).
Warning
Do not plug in the engine block
heater while the vehicle is parked
in a garage or under a carport.
Property damage or personal
injury may result. Always park the
vehicle in a clear open area away
from buildings or structures.
To Use the Engine Heater
1. Turn off the engine.