2012 GMC YUKON cooling

Black plate (10,1)GMC Yukon/Yukon XL Owner Manual - 2012
6-10 Lighting
The battery can be discharged at
idle if the electrical loads are very
high. This is true for all vehicles.
This is because the generator
(alternator) may not be spinning fast
enough at idle to produce all the
power that is needed for very high
electrical loads.
A high electrical load occurs when
several of the following are on, such
as: headlamps, high beams, fog
lamps, rear window defogger,
climate control fan at high speed,
heated seats, engine cooling fans,
trailer loads, and loads plugged into
accessory power outlets.
EPM works to prevent excessive
discharge of the battery. It does this
by balancing the generator's output
and the vehicle's electrical needs.
It can increase engine idle speed to
generate more power, whenever
needed. It can temporarily reduce
the power demands of some
accessories.Normally, these actions occur in
steps or levels, without being
noticeable. In rare cases at the
highest levels of corrective action,
this action may be noticeable to the
driver. If so, a Driver Information
Center (DIC) message might be
displayed, such as BATTERY LOW
START VEHICLE. If this message
displays, it is recommended that the
driver reduce the electrical loads as
much as possible and restart the
vehicle. See
Battery Voltage and
Charging Messages on page 5‑38.Battery Power Protection
This feature shuts off the dome, and
reading lamps if they are left on for
more than 10 minutes when the
ignition is off. This will keep the
battery from running down.

Black plate (1,1)GMC Yukon/Yukon XL Owner Manual - 2012
Climate Controls 8-1
Climate Controls
Climate Control Systems
Climate Control Systems . . . . . . 8-1
Dual Automatic Climate ControlSystem . . . . . . . . . . . . . . . . . . . . . . 8-4
Rear Climate Control System (Rear Climate
Control Only) . . . . . . . . . . . . . . . 8-10
Rear Climate Control System (Rear Climate with Rear Seat
Audio) . . . . . . . . . . . . . . . . . . . . . . 8-11
Air Vents
Air Vents . . . . . . . . . . . . . . . . . . . . . 8-13
Climate Control Systems
The heating, cooling, and ventilation in the vehicle can be controlled with
this system.
A. Fan Control
B. REAR (Rear Climate Control)
C. Recirculation
D. Air Delivery Mode Control
E. Air Conditioning F. Driver and Passenger
Temperature Controls
G. Rear Window Defogger
Temperature Control: Move the
thumbwheels up or down to
increase or decrease the
temperature on the driver side or
the passenger side of the vehicle for
the dual zone system.

Black plate (4,1)GMC Yukon/Yukon XL Owner Manual - 2012
8-4 Climate Controls
Dual Automatic Climate Control System
The heating, cooling, and ventilation in the vehicle can be controlled with
this system. The vehicle also has a flow-through ventilation system
described later in this section.
If the vehicle is a hybrid, see the hybrid supplement for more information.
A. Fan Control
B. AUTO (Automatic Operation)
C. Defrost
D. Recirculation
E. REAR (Rear Climate Control)F. Air Delivery Mode Control
G. Driver Temperature Control
H. Display
I. Power Button
J. Rear Window DefoggerK. Air Conditioning
L. PASS
M. Passenger Temperature Control
O(On/Off):
Press to turn the
climate control system on or off.
Outside air still enters the vehicle,
and is directed to the floor. This
direction can be changed by
pressing the mode button.
Recirculation can be selected once
you have selected vent or bi-level
mode. The temperature can also be
adjusted using either temperature
button. If the air delivery mode or
temperature settings are adjusted
with the system off, the display
illuminates briefly to show the
settings and then returns to off. The
system can be turned back on by
pressing either
O,D,C,#, the
defrost or the AUTO button.

Black plate (6,1)GMC Yukon/Yukon XL Owner Manual - 2012
8-6 Climate Controls
the system remains at the
maximum cooling setting. If a
temperature setting of 32°C
(90°F) is chosen, the system
remains at the maximum heat
setting. Choosing either
maximum setting will not cause
the vehicle to heat or cool any
faster.
Do not cover the solar sensor
located on the top of the instrument
panel near the windshield. This
sensor regulates air temperature
based on sun load and also turns
on the headlamps. For more
information on the solar sensor, see
“Sensors” later in this section.
To avoid blowing cold air in cold
weather, the system will delay
turning on the fan until warm air is
available. The length of delay
depends on the engine coolant
temperature. Pressing the fan
switch will override this delay and
change the fan to a selected speed.Manual Operation
D C(Fan Control): Press these
buttons to increase or decrease the
fan speed.
Pressing either fan button while in
automatic control places the fan
under manual control. The fan
setting remains displayed and the
AUTO light turns off. The air
delivery mode remains under
automatic control.
H G(Air Delivery Mode Control):
Press these buttons to change the
direction of the airflow in the vehicle.
Repeatedly press either button until
the desired mode appears on the
display. Pressing either mode button
while the system is off changes the
air delivery mode without turning the
system on. Pressing either mode
button while in automatic control
places the mode under manual
control. The air delivery mode setting is
displayed and the AUTO light turns
off. The fan remains under
automatic control.
H(Vent):
Air is directed to the
instrument panel outlets.
)(Bi-Level): Air is divided
between the instrument panel and
floor outlets. Some air is directed
towards the windshield and side
window outlets.
6(Floor): Air is directed to the
floor outlets, with some to the
windshield, side window outlets, and
second row floor outlets. In this
mode, the system automatically
selects outside air.

Black plate (11,1)GMC Yukon/Yukon XL Owner Manual - 2012
Driving and Operating 9-11
After Off-Road Driving
Remove any brush or debris that
has collected on the underbody,
or chassis, or under the hood.
These accumulations can be a fire
hazard.
After operation in mud or sand,
have the brake linings cleaned and
checked. These substances can
cause glazing and uneven braking.
Check the body structure, steering,
suspension, wheels, tires, and
exhaust system for damage and
check the fuel lines and cooling
system for any leakage.
More frequent maintenance
service is required. Refer to the
Maintenance Schedule for more
information.
Driving on Wet Roads
Rain and wet roads can reduce
vehicle traction and affect your
ability to stop and accelerate.
Always drive slower in these types
of driving conditions and avoid
driving through large puddles and
deep‐standing or flowing water.
{WARNING
Wet brakes can cause crashes.
They might not work as well in a
quick stop and could cause
pulling to one side. You could
lose control of the vehicle.
After driving through a large
puddle of water or a car/vehicle
wash, lightly apply the brake
pedal until the brakes work
normally.(Continued)
WARNING (Continued)
Flowing or rushing water creates
strong forces. Driving through
flowing water could cause the
vehicle to be carried away. If this
happens, you and other vehicle
occupants could drown. Do not
ignore police warnings and be
very cautious about trying to drive
through flowing water.

Black plate (13,1)GMC Yukon/Yukon XL Owner Manual - 2012
Driving and Operating 9-13
Hill and Mountain Roads
Driving on steep hills or through
mountains is different than driving
on flat or rolling terrain. Tips for
driving in these conditions include:
.Keep the vehicle serviced and in
good shape.
.Check all fluid levels and brakes,
tires, cooling system, and
transmission.
.Shift to a lower gear when going
down steep or long hills.
{WARNING
If you do not shift down, the
brakes could get so hot that they
would not work well. You would
then have poor braking or even
none going down a hill. You could
crash. Shift down to let the engine
assist the brakes on a steep
downhill slope.
{WARNING
Coasting downhill in N (Neutral)
or with the ignition off is
dangerous. The brakes will have
to do all the work of slowing down
and they could get so hot that
they would not work well. You
would then have poor braking or
even none going down a hill. You
could crash. Always have the
engine running and the vehicle in
gear when going downhill.
.Stay in your own lane. Do not
swing wide or cut across the
center of the road. Drive at
speeds that let you stay in your
own lane.
.Be alert on top of hills,
something could be in your lane
(stalled car, accident).
.Pay attention to special road
signs (falling rocks area, winding
roads, long grades, passing or
no-passing zones) and take
appropriate action.
Winter Driving
Driving on Snow or Ice
Drive carefully when there is snow
or ice between the tires and the
road, creating less traction or grip.
Wet ice can occur at about 0°C
(32°F) when freezing rain begins to
fall, resulting in even less traction.
Avoid driving on wet ice or in
freezing rain until roads can be
treated with salt or sand.
Drive with caution, whatever the
condition. Accelerate gently so
traction is not lost. Accelerating too
quickly causes the wheels to spin
and makes the surface under the
tires slick, so there is even less
traction.

Black plate (71,1)GMC Yukon/Yukon XL Owner Manual - 2012
Driving and Operating 9-71
3. When the wheel chocks are inplace, release the regular brakes
until the chocks absorb the load.
4. Reapply the brake pedal. Then apply the parking brake and shift
into P (Park).
5. If the vehicle is four-wheel-drive and has a two-speed transfer
case, be sure the transfer case
is in a drive gear and not in
N (Neutral).
6. Release the brake pedal.
{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 the engine has been left
running, the vehicle can move
suddenly. You or others could be
injured. To be sure the vehicle will (Continued)
WARNING (Continued)
not move, even when on fairly
level ground, use the steps that
follow.
Always put the shift lever fully in
P (Park) with the parking brake
firmly set.
If the transfer case on a
four-wheel-drive vehicle is in
N (Neutral), the vehicle will be
free to roll, even if the shift lever
is in P (Park). Be sure the transfer
case is in a drive gear —not in
N (Neutral).
Leaving After Parking on a Hill
1. Apply and hold the brake pedal.
2. Start the engine.
3. Shift into a gear. 4. Release the parking brake.
5. Let up on the brake pedal.
6. Drive slowly until the trailer is
clear of the chocks.
7. Stop and have someone pick up and store the chocks.
Maintenance When Trailer
Towing
The vehicle needs service more
often when pulling a trailer. See
Maintenance Schedule on
page 11‑3. Things that are
especially important in trailer
operation are automatic
transmission fluid, engine oil, axle
lubricant, belts, cooling system and
brake system. It is a good idea to
inspect these before and during
the trip.
Check periodically to see that all
hitch nuts and bolts are tight.

Black plate (73,1)GMC Yukon/Yukon XL Owner Manual - 2012
Driving and Operating 9-73
Use the following chart to determine how much the vehicle can weigh, based upon the vehicle model and options.Vehicle Axle Ratio Maximum Trailer Weight GCWR*
1500 Series 2WD Short Wheel Base
5.3L V8 3.082 495 kg (5,500 lbs) 4 990 kg (11,000 lbs)
5.3L V8 3.422 722 kg (6,000 lbs) 5 216 kg (11,500 lbs)
5.3L V8 K5L HD Cooling Pkg 3.423 856 kg (8,500 lbs) 6 350 kg (14,000 lbs)
1500 Series 2WD Long Wheel Base
5.3L V8 3.082 313 kg (5,100 lbs) 4 990 kg (11,000 lbs)
5.3L V8 3.422 540 kg (5,600 lbs) 5 216 kg (11,500 lbs)
5.3L V8 K5L HD Cooling Pkg 3.423 674 kg (8,100 lbs) 6 350 kg (14,000 lbs)
1500 Series 4WD Short Wheel Base 5.3L V8 3.082 359 kg (5,200 lbs) 4 990 kg (11,000 lbs)
5.3L V8 3.422 586 kg (5,700 lbs) 4 990 kg (11,000 lbs)
5.3L V8 K5L HD Cooling Pkg 3.423 720 kg (8,200 lbs) 6 350 kg (14,000 lbs)
1500 Series 4WD Long Wheel Base 5.3L V8 3.082 268 kg (5,000 lbs) 4 990 kg (11,000 lbs)
5.3L V8 3.422 495 kg (5,500 lbs) 5 216 kg (11,500 lbs)
5.3L V8 K5L HD Cooling Pkg 3.423 629 kg (8,000 lbs) 6 350 kg (14,000 lbs)