2011 CHEVROLET TAHOE ECU

Black plate (4,1)Chevrolet Tahoe and GMC Yukon/Yukon Denali Hybrid - 2011
9-4 Driving and Operating
Engine Coolant Heater
The engine coolant heater can
provide easier starting and better
fuel economy during engine
warm-up in cold weather conditions
at or below−18°C (0°F). Vehicles
with an engine heater should be
plugged in at least four hours before
starting. An internal thermostat in
the plug-end of the cord may exist
which will prevent engine coolant
heater operation at temperatures
above −18°C (0°F).
Using the Engine Coolant
Heater
1. Turn off the engine.
2. Open the hood and unwrap the
electrical cord. The cord is
secured to a wiring harness
between the engine and the
Hybrid Auxiliary Underhood
Fuse Block with a clip. Carefully
remove the wire tie which
secures the electrical cord. Do
not cut the electrical cord. 3. Plug the cord into a normal,
grounded 110-volt AC outlet.
{WARNING
Plugging the cord into an
ungrounded outlet could cause an
electrical shock. Also, the wrong
kind of extension cord could
overheat and cause a fire. You
could be seriously injured. Plug
the cord into a properly grounded
three-prong 110-volt AC outlet.
If the cord will not reach, use a
heavy-duty three-prong extension
cord rated for at least 15 amps.
4. Before starting the engine, be sure to unplug and store the
cord as it was before to keep it
away from moving engine parts.
If you do not, it could be
damaged. The length of time the heater should
remain plugged in depends on
several factors. Ask a dealer in the
area where you will be parking the
vehicle for the best advice on this.
Shifting Into Park
{WARNING
It can be dangerous to get out of
the vehicle if the shift lever is not
fully in P (Park) with the parking
brake firmly set. The vehicle can
roll. If you have left the engine
running, the vehicle can move
suddenly. You or others could be
injured. To be sure the vehicle will
not move, even when you are on
fairly level ground, use the steps
that follow. With four-wheel drive,
if the transfer case is in
N (Neutral), the vehicle will be
free to roll, even if the shift lever
is in P (Park). So, be sure the
transfer case is in a drive
(Continued)

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

Black plate (29,1)Chevrolet Tahoe and GMC Yukon/Yukon Denali Hybrid - 2011
Vehicle Care 10-29
7. Attach the air only hose (F) ontothe tire valve stem and press the
lever down to secure it.
8. Plug the power plug (C) into the accessory power outlet in the
vehicle. Unplug all items from
other accessory power outlets.
See “Power Outlets” in the
owner manual.
If the vehicle has an accessory
power outlet, do not use the
cigarette lighter.
If the vehicle only has a cigarette
lighter, use the cigarette lighter.
Do not pinch the power plug
cord in the door or window.
9. Start the vehicle. The vehicle must be running while using the
air compressor. 10. Press the on/off (D) button to
turn the compressor on.
The compressor will inflate the
tire with air only.
11. Inflate the tire to the recommended inflation
pressure using the pressure
gauge (E). The recommended
inflation pressure can be found
on the Tire and Loading
Information label. See Tire
Pressure on page 10‑17.
The pressure gauge (E) may
read higher than the actual tire
pressure while the compressor
is on. Turn the compressor off
to get an accurate reading. The
compressor may be turned on/
off until the correct pressure is
reached. 12. Press the on/off button (D) to
turn the tire sealant and
compressor kit off.
Be careful while handling the
tire sealant and compressor kit
as it could be warm after
usage.
13. Unplug the power plug (C) from the accessory power outlet in
the vehicle.
14. Disconnect the air only hose (C) from the tire valve
stem, by turning it
counterclockwise, and replace
the tire valve stem cap.
15. Replace the air only hose (F) and the power plug (C) back in
its original location.
16. Place the equipment in the original storage location in the
vehicle.

Black plate (37,1)Chevrolet Tahoe and GMC Yukon/Yukon Denali Hybrid - 2011
Vehicle Care 10-37
Dinghy Towing
Two-Wheel Drive Vehicles
Notice:If the vehicle is towed
with all four wheels on the
ground, the drivetrain
components could be damaged.
The repairs would not be covered
by the vehicle warranty. Do not
tow the vehicle with all four
wheels on the ground.
Two-wheel drive vehicles should not
be towed with all four wheels on the
ground. Two-wheel drive transmissions have no provisions
for internal lubrication while being
towed.
Four-Wheel Drive Vehicles
Use the following procedure to
dinghy tow a four-wheel drive
vehicle:
1. Position the vehicle being towed
behind the tow vehicle and shift
the transmission to P (Park).
2. Turn the engine off and firmly set the parking brake. See “Parking
Brake” in the owner manual. 3. Securely attach the vehicle
being towed to the tow vehicle.
{WARNING
Shifting a four-wheel-drive
vehicle's transfer case into
N (Neutral) can cause the vehicle
to roll even if the transmission is
in P (Park). The driver or others
could be injured. Make sure the
parking brake is firmly set before
the transfer case is shifted to
N (Neutral).
4. Shift the transfer case to N (Neutral). For more information
on“Shifting into N (Neutral)”, see
“Four Wheel Drive” in the owner
manual.
5. Release the parking brake only after the vehicle being towed is
firmly attached to the towing
vehicle.
6. Turn the ignition to LOCK/OFF and remove the key —the
steering wheel will still turn.

Black plate (39,1)Chevrolet Tahoe and GMC Yukon/Yukon Denali Hybrid - 2011
Vehicle Care 10-39
5. Shift the transfer case toN (Neutral). For more information
on“Shifting into N (Neutral)”, see
“Four Wheel Drive” in the owner
manual.
6. Secure the vehicle to the dolly following the manufacturer's
instructions.
7. Release the parking brake only after the vehicle being towed is
firmly attached to the towing
vehicle.
8. Turn the ignition to LOCK/OFF.
After towing, see “Shifting Out of
N (Neutral)” under“Four Wheel
Drive” in the owner manual.Dolly Towing –Rear Towing
(Rear Wheels Off the Ground)
Two‐Wheel Drive Vehicles
Use the following procedure to dolly
tow a two-wheel-drive vehicle from
the rear:
1. Attach the dolly to the tow
vehicle following the dolly
manufacturer's instructions.
2. Drive the rear wheels onto the dolly. 3. Firmly set the parking brake.
See “Parking Brake” in the
owner manual.
4. Put the transmission in P (Park).
5. Secure the vehicle to the dolly following the manufacturer's
instructions.
6. Use an adequate clamping device designed for towing to
ensure that the front wheels are
locked into the straight position.
7. Turn the ignition to LOCK/OFF.
Four‐Wheel Drive Vehicles
Use the following procedure to dolly
tow a four-wheel drive vehicle from
the rear:
1. Attach the dolly to the tow vehicle following the dolly
manufacturer's instructions.
2. Drive the rear wheels onto the dolly.

Black plate (40,1)Chevrolet Tahoe and GMC Yukon/Yukon Denali Hybrid - 2011
10-40 Vehicle Care
3. Firmly set the parking brake.See “Parking Brake” in the
owner manual.
4. Put the transmission in P (Park).
5. Secure the vehicle to the dolly following the manufacturer's
instructions.
6. Use an adequate clamping device designed for towing to
ensure that the front wheels are
locked into the straight position.{WARNING
Shifting a four-wheel-drive
vehicle's transfer case into
N (Neutral) can cause the vehicle
to roll even if the transmission is
in P (Park). The driver or others
could be injured. Make sure the
parking brake is firmly set before
the transfer case is shifted to
N (Neutral).
7. Shift the transfer case to N (Neutral). For more information
on“Shifting into N (Neutral)”, see
“Four Wheel Drive” in the owner
manual.
8. Turn the ignition to LOCK/OFF.
After towing, see “Shifting Out of
N (Neutral)” under“Four Wheel
Drive” in the owner manual.
Appearance Care
Exterior Care
When scraping the windshield glass
to remove ice and snow, stay clear
of the hybrid decal.
To have the hybrid decals removed
from the vehicle, please see your
dealer.