2010 GMC YUKON HYBRID coolant level

A. See“Engine Air Cleaner/Filter” in the owner
manual.
B. Drive Motor/Generator Control Module (DMCM). See Drive Motor/Generator Control Module
(DMCM) Cooling System on page 6‑9.
C. Engine Oil Dipstick. See “Engine Oil”in the owner
manual.
D. Automatic Transmission Fluid Dipstick. See Automatic Transmission Fluid on page 6‑5.
E. Brake Fluid Reservoir. See Brakes on page 6‑13.
F. See “Underhood Fuse Block” in the owner manual.
G. See “Windshield Washer Fluid” in the owner
manual.
H. Hybrid Auxiliary Fuse Block. See Underhood Fuse
Block on page 6‑26.
I. DMCM Coolant Surge Tank Pressure Cap. See Drive Motor/Generator Control Module (DMCM)
Coolant Surge Tank Pressure Cap on page 6‑8.
J. See “Coolant Surge Tank Pressure Cap” in the
owner manual.
K. Engine Oil Fill Cap. See “Engine Oil”in the owner
manual.Automatic Transmission Fluid
When to Check and Change Automatic
Transmission Fluid
It is usually not necessary to check the transmission
fluid level. The only reason for fluid loss is a
transmission leak or overheating the transmission.
If you suspect a small leak, then use the following
checking procedures to check the fluid level. However,
if there is a large leak, then it may be necessary to have
the vehicle towed to a dealer/retailer service department
and have it repaired before driving the vehicle further.
Notice: Use of the incorrect automatic transmission
fluid may damage the vehicle, and the damages may
not be covered by the vehicle's warranty. Always
use the automatic transmission fluid listed in
Recommended Fluids and Lubricants on page 7‑2.
Change the fluid and filter at the intervals listed in the
Maintenance Schedule. See Scheduled Maintenance in
the owner manual. Be sure to use the transmission fluid
listed in Recommended Fluids and Lubricants
on
page 7‑2.
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5. Safe operating level is within the HOT cross hatchband on the dipstick. If the fluid level is not within
the HOT band, and the transmission temperature
is between 60°C and 75°C (140°F and 167°F),
add or drain fluid as necessary to bring the level
into the HOT band. If the fluid level is low, add only
enough fluid to bring the level into the HOT band.
It does not take much fluid, generally less than
0.5 Liter (1 Pint). Do not overfill.
6. If the fluid level is in the acceptable range, push the dipstick back in all the way.
Consistency of Readings
Always check the fluid level at least twice using the
procedure described previously. Consistency
(repeatable readings) is important to maintaining proper
fluid level. If readings are still inconsistent, contact your
dealer/retailer.
Drive Motor/Generator Control
Module (DMCM) Coolant Surge Tank
Pressure Cap
See Engine Compartment
Overviewon page 6‑4for more information on
location.
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If the coolant inside the DMCM coolant surge tank is
boiling, do not do anything else until it cools down.
The coolant level should be at or above the FULL
COLD mark with the vehicle parked on a level surface.
If it is not, there might be a leak at the DMCM cooler
core, DMCM pressure cap, DMCM cooler hoses,
DMCM cooling pump or somewhere else in the DMCM
cooling system.
Notice:Running the engine when there is a leak in
the hybrid cooling system can cause the hybrid
cooling system to lose all coolant and can damage
the system. Get any leak fixed before you drive the
vehicle or run the engine.
How to Add Coolant to the DMCM
Coolant Surge Tank
If no problem has been found yet, check to see if
coolant is visible in the DMCM coolant surge tank.
If coolant is visible, add pre‐mixed DEX-COOL™
coolant, available at your dealer/retailer, at the DMCM
coolant surge tank, but be sure the DMCM cooling
system, including the DMCM coolant surge tank
pressure cap, is cool before you do it. Use the
procedure following.
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{WARNING:
Steam and scalding liquids from a hot cooling
system can blow out and burn you badly. They are
under pressure, and if you turn the coolant surge
tank pressure cap—even a little —they can come
out at high speed. Never turn the cap when the
cooling system, including the coolant surge tank
pressure cap, is hot. Wait for the cooling system
and coolant surge tank pressure cap to cool if you
ever have to turn the pressure cap.
Notice: Using coolant other than a pre‐mixed
DEX-COOL, available at your dealer/retailer, may
damage your vehicle. Any repairs would not be
covered by your warranty. Always use a pre‐mixed
DEX-COOL (silicate-free) coolant in your vehicle.
{WARNING:
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol
and it will burn if the engine parts are hot enough.
Do not spill coolant on a hot engine. If the DMCM coolant is empty , the vehicle must be
serviced by your dealer and a special fill procedure
must be followed.
Notice:
Attempting to fill the DMCM cooling surge
tank yourself when the fluid level is empty can
damage your vehicle. Your vehicle must be
serviced.1. Park the vehicle on a level surface and turn the vehicle off. Remove the DMCM coolant surge tank
pressure cap when the DMCM cooling system,
including the DMCM coolant surge tank pressure
cap and DMCM cooling hoses, are no longer hot.
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Turn the DMCM coolant surge tank pressure cap
slowly counterclockwise (left) about one full turn.
Wait 30 seconds.
2. Then keep turning the DMCM coolant surge tankpressure cap slowly, and remove it.
3. Add the pre‐mixed DEX‐COOL™, available at your dealer/retailer, 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/retailer, 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, your vehicle may need service. See your
dealer/retailer.
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.
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