2007 GMC YUKON heating

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 236. 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 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 432for 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 448for
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 236.
SeeOverheated Engine Protection Operating
Mode on page 450for information on driving to a
safe place in an emergency.
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.
SeeEngine Overheating on page 448for
more information.
254

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 448for 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 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 243andFuel on
page 423for 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.
LEFT REAR DOOR OPEN
If the driver’s side rear door is not fully closed and
the vehicle is in a drive gear, this message will
display and a chime will sound. Stop and turn off
the vehicle, check the door for obstructions,
and close the door again. Check to see if the
message still appears on the DIC.
255

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 233.
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
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.
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 237.
Reinstall the fuel cap fully. SeeFilling the Tank on
page 426. 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 (Using
DIC Buttons)” earlier in this section for 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 496,Tire Pressure Monitor System on
page 490, andInation - Tire Pressure on
page 488for more information.
260

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 349for 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.TURN SIGNAL ON
If a turn signal is left on for 3/4 of a mile (1.2 km),
this message will display and a chime will
sound. Move the turn signal/multifunction lever to
the off position.
WASHER FLUID LOW ADD FLUID
If the washer uid level is low, this message will
display. Adding washer uid to the windshield
washer reservoir will clear the message. See
Windshield Washer Fluid on page 458.
This message will clear itself after 10 seconds,
until the next ignition cycle.
261

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 156. 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.
CAUTION: (Continued)
CAUTION: (Continued)

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. SeeDual Automatic Climate
Control System on page 214.
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.
409

Turn Signals When Towing a Trailer
The arrows on your instrument panel will
ash whenever you signal a turn or lane change.
Properly hooked up, the trailer lamps will also
ash, telling other drivers you’re about to
turn, change lanes or stop.
When towing a trailer, the arrows on your
instrument panel will ash for turns even if the
bulbs on the trailer are burned out. Thus, you may
think drivers behind you are seeing your signal
when they are not. It’s important to check
occasionally to be sure the trailer bulbs are still
working.
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” underTowing a Trailer on page 400.
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 448.
411

Service........................................................ 420
Accessories and Modications................... 421
California Proposition 65 Warning.............. 421
Doing Your Own Service Work.................. 422
Adding Equipment to the Outside
of Your Vehicle...................................... 423
Fuel............................................................. 423
Gasoline Octane........................................ 423
Gasoline Specications.............................. 424
California Fuel........................................... 424
Additives................................................... 424
Fuels in Foreign Countries........................ 425
Filling the Tank......................................... 426
Filling a Portable Fuel Container............... 428
Checking Things Under the Hood.............. 428
Hood Release........................................... 429
Engine Compartment Overview.................. 430
Engine Oil................................................. 432
Engine Oil Life System.............................. 435Engine Air Cleaner/Filter............................ 437
Automatic Transmission Fluid.................... 440
Engine Coolant.......................................... 445
Coolant Surge Tank Pressure Cap............ 448
Engine Overheating................................... 448
Overheated Engine Protection
Operating Mode..................................... 450
Cooling System......................................... 451
Engine Fan Noise..................................... 456
Power Steering Fluid................................. 457
Windshield Washer Fluid........................... 458
Brakes...................................................... 459
Battery...................................................... 463
Jump Starting............................................ 464
All-Wheel Drive........................................... 469
Rear Axle.................................................... 470
Front Axle................................................... 471
Headlamp Aiming........................................ 473
Section 5 Service and Appearance Care
417

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 448.
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.
445