heating GMC YUKON XL 2007 User Guide

Rear Air Conditioning and Heating
System and Electronic Climate
Controls
If your vehicle has this system, the rear heat and
air conditioning controls are integrated with the
rear seat audio controls located in the center
console. The system can be controlled from the
front controls as well as the rear controls.
To turn the system on, press the AUX button on
the front climate control system, an indicator will be
lit. Pressing the AUX button the rst time will
turn the rear system on in a mimic mode. In this
mode, the airow in the rear will be approximately
the same direction, temperature, and fan speed
as the front. Pressing the AUX button again
will turn the rear system and the indicator off.If the rear controls are adjusted, the system will
enter a rear independent mode. Airow in the rear
will then be directed according to the settings of
rear controls. The rear system can be turned off by
pressing the AUX button on the front climate
control system and the indicator will turn off.
If the indicator in the front AUX button is off, the
rear system is off.
Rear Control Integrated with Rear Seat Audio
Controls
222

StabiliTrak®Indicator Light
If equipped, this warning
light should come on
briey when the engine
is started.
If the warning light does not come on then, have it
xed so it will be ready to warn you if there is a
problem. If it stays on, or comes on when you are
driving, there may be a problem with your
StabiliTrak
®system and your vehicle may need
service. When this warning light is on, the system
is off and will not limit wheel spin. Adjust your
driving accordingly.
This light will also ash when the StabiliTrak
®
system is active.
If the StabiliTrak
®system warning light comes on
and stays on for an extended period of time
when the system is turned on, your vehicle needs
service. SeeStabiliTrak
®System on page 348
for more information.
Engine Coolant Temperature Gage
This gage shows the engine coolant temperature.
It also provides an indicator of how hard your
vehicle is working. During a majority of the
operation, the gage will read 210°F (100°C) or
less. If you are pulling a load or going up hills, it is
normal for the temperature to uctuate and
approach the 250°F (122°C) mark. If the gage
reaches the 260°F (125°C) mark, it indicates that
the cooling system is working beyond its
capacity.
SeeEngine Overheating on page 452.
United StatesCanada
234

ENGINE HOT A/C (Air Conditioning)
TURNED OFF
This message will display when the engine coolant
becomes hotter than the normal operating
temperature. SeeEngine Coolant Temperature
Gage on page 234. To avoid added strain on a
hot engine, the air conditioning compressor
automatically turns off. When the coolant
temperature returns to normal, the air conditioning
compressor will turn back on. You can continue
to drive your vehicle.
If this message continues to appear, have the
system repaired by your GM dealer as soon
as possible to avoid damage to your engine.
ENGINE OIL LOW ADD OIL
If your vehicle has an oil level sensor and the oil
level in the vehicle is low, this message will
display. Check the oil level and correct it as
necessary. You may need to let the vehicle cool
or warm up and cycle the ignition to be sure
this message will clear.
This message will clear itself after 10 seconds,
until the next ignition cycle. SeeEngine Oil
on page 438for additional information.
ENGINE OVERHEATED IDLE ENGINE
Notice:If you drive your vehicle while the
engine is overheating, severe engine damage
may occur. If an overheat warning appears
on the instrument panel cluster and/or
DIC, stop the vehicle as soon as possible.
SeeEngine Overheating on page 452for more
information.
This message will display when the engine coolant
temperature is too hot. Stop and allow the
vehicle to idle until it cools down. SeeEngine
Coolant Temperature Gage on page 234.
SeeOverheated Engine Protection Operating
Mode on page 454for information on driving to a
safe place in an emergency.
256

ENGINE OVERHEATED STOP ENGINE
Notice:If you drive your vehicle while the
engine is overheating, severe engine damage
may occur. If an overheat warning appears
on the instrument panel cluster and/or
DIC, stop the vehicle as soon as possible. See
Engine Overheating on page 452for more
information.
If the engine cooling system reaches unsafe
temperatures for operation, this message will
display and a chime will sound. Stop and turn off
the vehicle as soon as it is safe to do so to avoid
severe damage. This message will clear when the
engine has cooled to a safe operating temperature.
ENGINE POWER IS REDUCED
This message will display and a chime will sound
when the cooling system temperature gets too
hot and the engine further enters the engine
coolant protection mode. SeeEngine Overheating
on page 452for further information.This message will also display when the vehicle’s
engine power is reduced. Reduced engine
power can affect the vehicle’s ability to accelerate.
If this message is on, but there is no reduction
in performance, proceed to your destination.
The performance may be reduced the next time
the vehicle is driven. The vehicle may be driven at
a reduced speed while this message is on, but
acceleration and speed may be reduced. Anytime
this message stays on, the vehicle should be
taken to your GM dealer for service as soon as
possible.
FUEL LEVEL LOW
If the fuel level is low, this message will display
and a chime will sound. Refuel as soon as
possible. SeeFuel Gage on page 243and
Fuel on page 428for more information.
HOOD OPEN
If the hood is not fully closed, this message will
display and a chime will sound. Stop and turn off
the vehicle, check the hood for obstructions, and
close the hood again. Check to see if the message
still appears on the DIC.
257

SERVICE TRACTION CONTROL
If your vehicle has StabiliTrak®, this message will
display when there is a problem with the traction
control system. When this message is displayed,
the system will not limit wheel spin. Adjust
your driving accordingly. See your GM dealer for
service. SeeStabiliTrak
®System on page 348
for more information.
STABILITRAK OFF
If your vehicle has StabiliTrak®, this message will
display when you turn off StabiliTrak®, or when
the stability control has been automatically
disabled. To limit wheel spin and realize the full
benets of the stability enhancement system, you
should normally leave StabiliTrak
®on. However,
you should turn StabiliTrak®off if your vehicle gets
stuck in sand, mud, ice, or snow and you want
to rock your vehicle to attempt to free it, or if you
are driving in extreme off-road conditions and
require more wheel spin. SeeIf Your Vehicle is
Stuck in Sand, Mud, Ice, or Snow on page 388.
To turn the StabiliTrak
®system on or off, see
StabiliTrak®System on page 348.There are several conditions that can cause this
message to appear.
One condition is overheating, which could
occur if StabiliTrak®activates continuously
for an extended period of time.
The message will also be displayed if the
brake system warning light is on. See
Brake System Warning Light on page 232.
The message could be displayed if the stability
system takes longer than usual to complete its
diagnostic checks due to driving conditions.
If an engine or vehicle related problem has
been detected and the vehicle needs
service, the message will appear. See your
GM dealer.
The message will also appear if the vehicle is
shifted into 4LO.
The message will turn off as soon as the conditions
that caused the message to be displayed are no
longer present.
262

TIGHTEN GAS CAP
If the vehicle’s fuel cap is not tightened properly,
this message may display along with the check
engine light on the instrument panel cluster.
SeeMalfunction Indicator Lamp on page 236.
Reinstall the fuel cap fully. SeeFilling the Tank on
page 432. The diagnostic system can determine
if the fuel cap has been left off or improperly
installed. A loose or missing fuel cap will allow fuel
to evaporate into the atmosphere. A few driving
trips with the cap properly installed should turn this
light and message off.
TIRE LEARNING ACTIVE
If your vehicle has a Tire Pressure Monitor (TPM)
system, this message will display when the system
is re-learning the tire positions on your vehicle. See
DIC Operation and Displays (With DIC Buttons) on
page 244orDIC Operation and Displays (Without
DIC Buttons) on page 251for more information.
The tire positions must be re-learned after rotating
the tires or after replacing a tire or sensor. SeeTire
Inspection and Rotation on page 497,Tire Pressure
Monitor System on page 492, andInation - Tire
Pressure on page 490for more information.
TRACTION CONTROL OFF
If your vehicle has StabiliTrak®, this message will
display when the traction control system is
turned off. Adjust your driving accordingly.
SeeStabiliTrak
®System on page 348for more
information.
TRANSMISSION HOT IDLE ENGINE
Notice:If you drive your vehicle while
the transmission uid is overheating and the
transmission temperature warning is displayed
on the instrument panel cluster and/or DIC,
you can damage the transmission. This could
lead to costly repairs that would not be
covered by your warranty. Do not drive your
vehicle with overheated transmission uid
or while the transmission temperature warning
is displayed.
If the transmission uid in the vehicle gets hot, this
message will display along with a continuous
chime. Driving with the transmission uid
temperature high can cause damage to the vehicle.
Stop the vehicle and let it idle to allow the
transmission to cool. This message will clear and
the chime will stop when the uid temperature
reaches a safe level.
263

Driving with a Trailer
{CAUTION:
If you have a rear-most window open and
you pull a trailer with your vehicle, carbon
monoxide (CO) could come into your
vehicle. You cannot see or smell CO. It can
cause unconsciousness or death. See
Engine Exhaust on page 155. To maximize
your safety when towing a trailer:
Have your exhaust system inspected
for leaks, and make necessary repairs
before starting on your trip.
Keep the rear-most windows closed.If exhaust does come into your vehicle
through a window in the rear or another
opening, drive with your front, main
heating or cooling system on and with
the fan on any speed. This will bring
fresh, outside air into your vehicle.
Do not use the climate control setting
for maximum air because it only
recirculates the air inside your vehicle.
SeeClimate Control System on
page 210.Towing a trailer requires a certain amount of
experience. Before setting out for the open road,
you’ll want to get to know your rig. Acquaint yourself
with the feel of handling and braking with the added
weight of the trailer. And always keep in mind that
the vehicle you are driving is now a good deal
longer and not nearly as responsive as your vehicle
is by itself.
Before you start, check all trailer hitch parts and
attachments, safety chains, electrical connector,
lamps, tires and mirror adjustment. If the trailer has
electric brakes, start your vehicle and trailer moving
and then apply the trailer brake controller by hand
to be sure the brakes are working. This lets you
check your electrical connection at the same time.
During your trip, check occasionally to be sure
that the load is secure, and that the lamps and any
trailer brakes are still working.
416

Driving On Grades
Reduce speed and shift to a lower gearbefore
you start down a long or steep downgrade. If you
don’t shift down, you might have to use your
brakes so much that they would get hot and no
longer work well.
You can tow in DRIVE (D). You may want to shift
the transmission to THIRD (3) or, if necessary,
a lower gear selection if the transmission shifts too
often (e.g., under heavy loads and/or hilly
conditions).
You may also want to activate the tow/haul mode
if the transmission shifts too often. See “Tow/Haul
Mode” earlier in this section for more information.
When towing at high altitude on steep uphill
grades, consider the following: Engine coolant at
or near sea level will boil at a lower temperature
than at higher altitudes. If you turn your engine off
immediately after towing at high altitude on
steep uphill grades, your vehicle may show signs
similar to engine overheating.To avoid this, let the engine run while parked
(preferably on level ground) with the automatic
transmission in PARK (P) for a few minutes before
turning the engine off. If you do get the overheat
warning, seeEngine Overheating on page 452.
Parking on Hills
{CAUTION:
You really should not park your vehicle,
with a trailer attached, on a hill. If
something goes wrong, your rig could
start to move. People can be injured, and
both your vehicle and the trailer can be
damaged.
But if you ever have to park your rig on a hill,
here’s how to do it:
1. Apply your regular brake, but don’t shift into
PARK (P) yet.
2. Have someone place chocks under the trailer
wheels.
418

Service.........................................................426
Accessories and Modications....................426
California Proposition 65 Warning...............427
Doing Your Own Service Work...................427
Adding Equipment to the Outside of
Your Vehicle...........................................428
Fuel..............................................................428
Gasoline Octane........................................428
Gasoline Specications...............................428
California Fuel............................................429
Additives....................................................429
Fuel E85 (85% Ethanol).............................430
Fuels in Foreign Countries.........................431
Filling the Tank..........................................432
Filling a Portable Fuel Container................434
Checking Things Under the Hood..............434
Hood Release............................................435
Engine Compartment Overview...................436
Engine Oil..................................................438
Engine Oil Life System...............................441
Engine Air Cleaner/Filter.............................443
Automatic Transmission Fluid.....................445
Engine Coolant...........................................449Coolant Surge Tank Pressure Cap.............451
Engine Overheating....................................452
Overheated Engine Protection
Operating Mode......................................454
Cooling System..........................................455
Engine Fan Noise......................................460
Power Steering Fluid..................................461
Windshield Washer Fluid............................462
Brakes.......................................................463
Battery.......................................................466
Jump Starting.............................................467
Rear Axle.....................................................472
Four-Wheel Drive.........................................473
Front Axle....................................................474
Headlamp Aiming........................................475
Bulb Replacement........................................478
Halogen Bulbs............................................478
Taillamps, Turn Signal, Stoplamps and
Back-up Lamps.......................................478
License Plate Lamp....................................480
Replacement Bulbs....................................481
Section 5 Service and Appearance Care
423

Engine Coolant
The cooling system in your vehicle is lled with
DEX-COOL®engine coolant. This coolant is
designed to remain in your vehicle for ve years or
150,000 miles (240 000 km), whichever occurs
rst, if you add only DEX-COOL
®extended
life coolant.
The following explains your cooling system and
how to add coolant when it is low. If you have
a problem with engine overheating, seeEngine
Overheating on page 452.A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
Give freezing protection down to
−34°F (−37°C).
Give boiling protection up to 265°F (129°C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning lights and gages work as they
should.
Notice:Using coolant other than DEX-COOL
®
may cause premature engine, heater core,
or radiator corrosion. In addition, the engine
coolant may require changing sooner, at
the rst maintenance service after each
30,000 miles (50 000 km) or 24 months,
whichever occurs rst. Any repairs would not
be covered by your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your
vehicle.
449