Page 57 of 98
Black plate (9,1)Chevrolet Tahoe and GMC Yukon/Yukon Denali Hybrid - 2011
Vehicle Care 10-9
Drive Motor/Generator
Control Module (DMCM)
Coolant Surge Tank
Pressure Cap
SeeEngine Compartment Overview
on page 10‑4 for more information
on location.
The Drive Motor/Generator Control
Module (DMCM) coolant surge tank
pressure cap must be fully installed
on the hybrid coolant surge tank.
Notice: If the pressure cap is not
tightly installed, coolant loss and
possible damage to the Drive
Motor/Generator Control
Module (DMCM) may occur. Be
sure the cap is properly and
tightly secured.
Drive Motor/Generator
Control Module (DMCM)
Cooling System
In addition to the regular cooling
system, the vehicle also has a
cooling system for the DMCM
system. This system is serviced
differently than the vehicle's main
cooling system. The DMCM cooling
system includes the DMCM coolant
surge tank, DMCM surge tank
pressure cap, DMCM cooling
pumps, hybrid cooling radiator and
the Drive Motor/Generator Control
Module (DMCM). The DMCM
cooling system uses a 50/50
pre-mixed DEX-COOL
®coolant and
deionized water available at your
dealer. See “Engine Coolant” and
“Cooling System” in the owner
manual for more information.
When it is safe to lift the hood:
A. Drive Motor/Generator Control Module (DMCM)
B. Engine Coolant Surge Tank Pressure Cap
C. DMCM Coolant Surge Tank/ Engine Coolant Surge Tank
D. DMCM Cooling Hoses (Out of View)
E. DMCM Coolant Tank Pressure Cap
Page 58 of 98
Black plate (10,1)Chevrolet Tahoe and GMC Yukon/Yukon Denali Hybrid - 2011
10-10 Vehicle Care
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, 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.
{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.
Page 59 of 98
Black plate (11,1)Chevrolet Tahoe and GMC Yukon/Yukon Denali Hybrid - 2011
Vehicle Care 10-11
Notice:Using coolant other than
a pre‐mixed DEX-COOL, available
at your dealer, 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. Turn the DMCM
coolant surge tank pressure cap
slowly counterclockwise (left)
about one full turn. Wait
30 seconds.2. Then keep turning the DMCMcoolant 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.
Page 60 of 98
Black plate (12,1)Chevrolet Tahoe and GMC Yukon/Yukon Denali Hybrid - 2011
10-12 Vehicle Care
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.
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.
Power Steering Fluid
The vehicle has electric power
steering and does not use power
steering fluid.
Battery
This vehicle has a standard 12‐volt
battery and a high voltage hybrid
battery.
Refer to the replacement number on
the original battery label when a
new standard 12‐volt battery is
needed. Only a trained service technician
with the proper knowledge and tools
should inspect, test, or replace the
hybrid battery. See your dealer if the
hybrid battery needs service. The
dealer has information on how to
recycle the hybrid battery. There
is also information available at
http://www.recyclemybattery.com.
If an airbag inflates or the vehicle
has been in a crash, the vehicle's
sensing system might command the
automatic hybrid battery disconnect
to open. See
Replacing Airbag
System Parts After a Crash on
page 3‑2 for more information.
{DANGER
Battery posts, terminals, and
related accessories contain lead
and lead compounds, chemicals
known to the State of California to
cause cancer and reproductive
harm. Wash hands after handling.
Page 61 of 98
Black plate (13,1)Chevrolet Tahoe and GMC Yukon/Yukon Denali Hybrid - 2011
Vehicle Care 10-13
Vehicle Storage
{WARNING
Batteries have acid that can burn
you and gas that can explode.
You can be badly hurt if you are
not careful. SeeJump Starting on
page 10‑32 for tips on working
around a battery without
getting hurt.
Infrequent Usage: Remove the
12‐volt battery black, negative (−)
cable from the battery to keep the
battery from running down.
Extended Storage: Remove the
12‐volt battery black, negative (−)
cable from the battery or use a
battery trickle charger.
Remember to reconnect the battery
when ready to drive the vehicle.
Bulb Replacement
For the proper type of replacement
bulbs, see Replacement Bulbs on
page 10‑14.
For any bulb‐changing procedure
not listed in this section, contact
your dealer.
Taillamps, Turn Signal,
Stoplamps, and Back-Up
Lamps
A. Taillamp/Stoplamp
B. Back-up Lamp
C. Turn Signal Lamp
D. Sidemarker Lamp
If the taillamp/stoplamp (A) needs to
be replaced, see your dealer.
1. Open the liftgate. See “Power
Liftgate” in the owner's manual.
2. Remove the two screws from the
taillamp assembly.
Page 62 of 98
Black plate (14,1)Chevrolet Tahoe and GMC Yukon/Yukon Denali Hybrid - 2011
10-14 Vehicle Care
3. Pull the taillamp assemblyrearward disengaging the two
outer pins on the taillamp
assembly from the vehicle.
4. Turn the bulb socket counterclockwise to remove it
from the taillamp assembly.
5. Pull the old bulb straight out from the bulb socket.
6. Press a new bulb into the bulb socket and insert it into the
taillamp assembly. Turn the bulb
socket clockwise into the
taillamp assembly until it clicks.
7. Reinstall the taillamp assembly. When reinstalling, make sure to
line up the pins on the taillamp
assembly with the vehicle. If this
is not done the taillamp
assembly cannot be correctly
installed.Replacement Bulbs
Exterior Lamp Bulb
Number
Back-up Lamp and
Rear Turn
Signal Lamp 3156
Sidemarker Lamp 194
For replacement bulbs not listed
here, contact your dealer.
Electrical System
High Voltage Devices and
Wiring
{WARNING
Exposure to high voltage can
cause shock, burns, and even
death. The high voltage systems
in your vehicle can only be
serviced by technicians with
special training.
High voltage devices are
identified by labels. Do not
remove, open, take apart,
or modify these devices. High
voltage cable or wiring has
orange covering. Do not probe,
tamper with, cut, or modify high
voltage cable or wiring.
Page 63 of 98
Black plate (15,1)Chevrolet Tahoe and GMC Yukon/Yukon Denali Hybrid - 2011
Vehicle Care 10-15
Fuses and Circuit
Breakers
The wiring circuits in the vehicle are
protected from short circuits by a
combination of fuses, circuit
breakers and fusible thermal links.
This greatly reduces the chance of
fires caused by electrical problems.
Be sure you replace a bad fuse with
a new one of the identical size and
rating.If you ever have a problem on the
road and do not have a spare fuse,
you can borrow one that has the
same amperage. Just pick some
feature of the vehicle that you can
get along without, like the radio or
cigarette lighter, and use its fuse,
if it is the correct amperage.
Replace it as soon as you can.
The vehicle also has a special fuse
in the battery box for the 300-volt
batteries. If this fuse has failed and
needs to be replaced, the vehicle
will be disabled and you will need to
have the vehicle repaired by your
dealer. Do not attempt to
self-service this fuse.
Engine Compartment
Fuse Block
Hybrid Auxiliary Engine
Compartment Fuse Block
The hybrid auxiliary engine
compartment fuse block is located
in the engine compartment near the
front of the vehicle. Lift the cover for
access to the fuse/relay block. See
Engine Compartment Overview on
page 10‑4
for more information on
its location. For more information on
the main underhood fuse block, see
“Engine Compartment Fuse Block”
in the owner manual.
Page 64 of 98
Black plate (16,1)Chevrolet Tahoe and GMC Yukon/Yukon Denali Hybrid - 2011
10-16 Vehicle Care
FusesUsage
1 ACPO (SUV Only)
2 BECM FAN
3 ACCM
4 CAB HTR PMP Fuses
Usage
5 EMPTY
6 COOL PUMP
7 EPS
8 Drive Motor/Generator
Control Module 1 Fuses
Usage
9 Drive Motor/Generator
Control Module 2
10 BECM
J‐Case Usage
FAN 1 Cooling Fan 1
TRANS PUMP Auxiliary
Transmission Fluid Pump
FAN 2 Cooling Fan 2
CAB
HTR PMP Cab Heater Pump
Relays Usage
CAB
HTR
PUMP Cabin Heater Pump
COOL
PUMP Coolant Pump
FAN LOW Cooling Fan Low
Speed Relay
