Chevrolet/GMC Duramax Diesel Supplement (GMNA-Localizing-U.S./Canada-
11354421) - 2018 - CRC - 10/10/17
6 In Brief
Heater Performance Mode
(8-Cylinder Pickup Models Only)
When cold weather conditions are
detected, the transmission raises
part throttle upshift points after the
1 (First) to 2 (Second) upshift to
increase engine speed. This feature
shortens engine and cab warm up
times.
When the transmission is in this
mode, upshifts may be delayed.
This is normal and does not indicate
an operational problem.
Four-Wheel Drive (8-Cylinder
Pickup Models Only)
When operating in 4
n
(Four-Wheel-Drive Low), there is a
very deep gear reduction. The
resulting shifts will feel exaggerated.
Performance and
Maintenance
Engine Oil Life System
The engine oil life system calculates
engine oil life based on vehicle use
and displays the CHANGE ENGINE
OIL SOON message when it is time
to change the engine oil and filter.
The oil life system should be reset
to 100% only following an oil
change. See “Engine Oil Life
System” in the owner’s manual.
Diesel Particulate Filter
The Duramax engine is equipped
with a Diesel Particulate Filter (DPF)
that will filter or trap particulates.
The DPF is under the vehicle in the
exhaust system.
Depending on a number of factors
monitored by the engine computer,
the DPF will need to be cleaned of
accumulated solids. When a
cleaning is needed, the engine
computer will initiate a cleaning
action by warming the exhaust gas
temperature. This feature has been
designed to operate automatically,
with limited operator involvement or
awareness.
Noise may be heard at low speeds
when the emission controls are
active. This is normal.
Cleaning the DPF (Exhaust
Filter)
While the DPF cleaning is
automatically controlled by the
engine computer, the Driver
Information Center (DIC) may
display a message. The vehicle will
need to operate continuously until
the message is no longer displayed.
Cleaning occurs most effectively
above 50 km/h (30 mph). If the
vehicle is returned to idle during the
cleaning process, the driver may
notice a slightly different sound or a
slightly elevated engine idle speed.
This is normal. No action is required
on the part of the driver during a
regular DPF cleaning. See Diesel
Particulate Filter 0 34.