GMC Chevrolet Tahoe 2012 Manual page 60

Chevrolet Tahoe and GMC Yukon/Yukon Denali Hybrid - 2012
10-12 Vehicle Care
2. Then keep turning the DMCM
coolant surge tank pressure cap
slowly, and remove it.
3. Add the pre mixed DEX COOL,
available at your dealer, to the
DMCM coolant surge tank until
the level reaches the FULL
COLD mark.
4. Turn the ignition to ON/RUN
without starting the engine.
The hybrid cooling pumps will
run and any trapped air will
purge to the surge tank.
5. Add the pre mixed DEX COOL,
available at your dealer, until the
coolant level is maintained at the
FULL COLD mark. This should
take no longer than two minutes
of hybrid cooling pump
operation.
If the level cannot be kept at the
FULL COLD level, the vehicle
may need service. See your
dealer.
Black plate (12,1)
6. Then replace the DMCM
coolant surge tank pressure cap.
Be sure the pressure cap is
hand-tight and fully seated.
Notice: Using tap water, cooling
system sealers or conditioners in
an attempt to stop coolant leaks
can damage the DMCM and
engine cooling systems. Never
use tap water, cooling system
sealers or conditioners in your
cooling system.