Idle Shutdown; High Idle System - Chevrolet 4500 HD 2023 Manual

If the system senses any of the following
conditions: high engine temperature, low
engine oil pressure or low engine coolant,
the corresponding warning light and engine
alarm (shutdown) warning light will come
on. If the engine alarm (shutdown) warning
light comes on, you will also hear a tone
alarm.
If your vehicle has the engine shutdown
feature, your engine will shut down in
30 seconds.
Pull safely off the road and shut off the
engine. Do not start it until the cause of the
problem is known, and the problem is fixed.
However, if the engine shuts down when
you are still in traffic, you can restart the
engine and get another 30 seconds of
operation. Do this only if you have to, since
there is a problem that can harm the engine
if it is not fixed. See Engine Shutdown
Warning Light 0 62.

Idle Shutdown

Idle Stop is a dealer programmable function
which will automatically turn off the engine,
at idle, when specific programmed
conditions are met. See your dealer for
details. When the Idle Stop light comes on,
it alerts you that programmed conditions
have been met and the engine is about to
shut down. This light stays on after the
engine has stopped. This indicator light will
come on when the engine control switch is
turned to the ON position and then should
go out after approximately 3 seconds.
If the idling stop function does not initiate,
a transmission related problem may have
occurred. Please contact your dealer. (There
is a Diagnostic Trouble Code (DTC) that
inhibits the idling stop function when the
Service Transmission Warning Light is not
illuminated).

High Idle System

Use high idle mode to increase engine idle
speed to 1,200 r/min when the vehicle is
stationary.
Driving and Operating 143