Chevrolet GMC Duramax 2023 Manual page 18

The DPF, the tailpipe, and other exhaust
system components must not be altered.
Inspect regularly and clean any mud or dirt
from the exhaust cooler, especially where
the exhaust cooler connects to the tailpipe
and the openings where fresh air enters the
cooler.
The DPF will clean itself as part of normal
operation. Several factors including fuel
consumed, hours of engine operation, and
miles driven are monitored by the Engine
Control Module (ECM). The self-cleaning
occurs approximately once per tank of fuel.
Vehicles with the DPF have specific fuel and
engine oil requirements. See Fuel for Diesel
Engines 0 23 and
Engine Oil 0 47.
Caution
Damage can occur to the DPF
components if the required Ultra Low
Sulfur Diesel (15 ppm sulfur maximum)
fuel and engine oil specified in the
Recommended Fluids and Lubricants
section of this manual are not used. This
damage would not be covered by the
vehicle warranty.
Under certain conditions, such as idling or
very short trips, the self-cleaning process has
less efficiency and cannot be completed.
To resolve this, continue driving safely at a
steady speed as close to the posted speed
limit as possible, preferably without
stopping, until the message turns off. This
can take up to 30 minutes.
Warning
During DPF self cleaning or during
extended idling in P (Park), the exhaust
system and exhaust gases are very hot.
Things that burn could touch hot exhaust
parts under the vehicle and ignite. You or
others could be burned. Do not park,
or idle for an extended period of time,
near or over papers, leaves, dry grass,
or other things that can burn. Keep the
exhaust area clear of material that could
ignite or burn. See Parking over Things
That Burn in the owner s manual.
Driving and Operating
Caution
Avoid extended idling because the DPF
system is not capable of self-cleaning at
idle. During extended idling, monitor the
instrument cluster lights and DIC for
messages and take appropriate action.
Continued idling with the warning light/
message on could cause damage to the
DPF requiring repair and possible
replacement that might not be covered
by the vehicle warranty.
During self-cleaning there will be a change
in the exhaust sound and engine idle speed.
Along with this, a burning smell and
reduction in fuel economy may be noticed.
This is normal.
If the vehicle is idled or driven on very short
trips with the DPF warning message on and
the exhaust filter is not cleaned as required,
the malfunction indicator lamp and a DIC
message will display. See your dealer. Also
see Malfunction Indicator Lamp (Check
Engine Light) 0 6.
See Accessories and Modifications 0 45 if
you are adding accessories or modifying the
vehicle.
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