off as you start to drive. This could be
an early indicator that your tire pres-
sures are getting low and the tires need
to be inflated to the proper pressure.
See Section 5 of your Owner Manual.
17
Note: The Tire Pressure Monitor can
alert you about low tire pressure, but it
doesn’t replace normal monthly tire
maintenance.
The Duramax Diesel engine is equipped
with a Diesel Particulate Filter (DPF)
that will filter or trap particulates (solid
particles in the exhaust exhibited as
black smoke) before they can be emit-
ted into the atmosphere. The DPF will
occasionally need to be cleaned of
accumulated solids. During a cleaning,
the exhaust gas temperature is warmed
so that the accumulated particulate mat-
ter in the DPF will be safely converted to
harmless gases. This feature has been
designed to operate automatically, with
limited driver involvement.
For effective DPF cleaning, the vehicle
will need to operate continuously for
approximately 20 minutes and at speeds
greater than 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.
If the vehicle is not being operated in a
manner to allow effective automatic DPF
cleaning, the CLN EXH FILTER warning
lamp will illuminate.
See your Duramax Diesel Engine Owner
Manual for more information.
Diesel Particulate Filter
(if equipped)
Oil Life System
The Oil Life System calculates engine
oil life based on vehicle use and
displays the CHANGE ENGINE OIL
SOON message when it’s necessary to
change your engine oil and filter. This is
based on engine operation and driving
conditions, not mileage. The Oil Life
System should be reset to 100% only
following an oil change.
To reset the Oil Life System:
1. Turn the ignition key to Run with the
engine off.
2. Fully press and release the accelera-
tor pedal slowly three times within
five seconds.
3. Turn the key to Lock.
See Section 5 of your Owner Manual.
