Technical data

Black plate (3,1)
Chevrolet/GMC Duramax Diesel Supplement (GMNA Localizing-U.S./Canada-
7132827) - 2015 - CRC - 10/21/14
Driving and Operating 9-3
If the vehicle is not out of fuel, and
the engine will not start:
Turn the ignition key to ON/RUN.
After the wait-to-start light goes off,
turn the ignition key to START.
If the light does not go off, wait a
few seconds, then try starting the
engine again. See your dealer as
soon as you can for a starting
system check.
If the light comes on and then goes
off and you know the batteries are
charged, but the engine still will not
start, the vehicle needs service.
If the light does not come on when
the engine is cold, the vehicle
needs service.
If the batteries do not have enough
charge to start the engine, see
“Battery” in the owner manual.
Check that the correct engine oil
has been used and changed at
appropriate intervals. If the wrong oil
is used, the engine may be harder
to start.
Be sure you are using the proper
fuel for existing weather conditions.
See Fuel for Diesel Engines on
page 9-21.
If the engine starts, runs a short
time, then stops, the vehicle needs
service.
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Warning
Do not use gasoline or starting
aids, such as ether, in the air
intake. They could damage the
engine, which may not be
covered by the vehicle warranty.
They could also cause a fire,
which could cause serious
personal injury.
Engine Idle Variations
Under certain conditions the engine
idle speed can vary or be elevated.
Change in idle speed is normal and
does not indicate a problem. Normal
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 rpm for pickup models or
1200 rpm for van models 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. For truck
models, there may be two methods
of activating the elevated idle.
To turn this feature on or off:
1. Turn the ignition to ON/RUN,
with the vehicle off.
2. Press the accelerator pedal to
the floor and hold while quickly
pressing the brake pedal three
times in less than eight seconds.
3. Release the accelerator pedal
and start the engine.