2007 GMC YUKON coolant temperature

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

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

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

Coolant Surge Tank Pressure Cap
Notice:If the pressure cap is not tightly
installed, coolant loss and possible engine
damage may occur. Be sure the cap is properly
and tightly secured.
The coolant surge tank pressure cap must be fully
installed on the coolant surge tank. SeeEngine
Compartment Overview on page 430for more
information on location.
Engine Overheating
You will nd a coolant temperature gage on your
vehicle’s instrument panel. SeeEngine Coolant
Temperature Gage on page 236.
In addition, you will nd an ENGINE
OVERHEATED STOP ENGINE, ENGINE
OVERHEATED IDLE ENGINE, and an ENGINE
POWER IS REDUCED message in the Driver
Information Center (DIC) on the instrument panel.
SeeDIC Warnings and Messages on page 252.
If Steam Is Coming From Your Engine
{CAUTION:
Steam from an overheated engine can burn
you badly, even if you just open the hood.
Stay away from the engine if you see or
hear steam coming from it. Just turn it off
and get everyone away from the vehicle
until it cools down. Wait until there is no
sign of steam or coolant before you open
the hood.
If you keep driving when your engine is
overheated, the liquids in it can catch re.
You or others could be badly burned.
Stop your engine if it overheats, and get
out of the vehicle until the engine is cool.
SeeOverheated Engine Protection
Operating Mode on page 450for
information on driving to a safe place
in an emergency.
448

4. With the coolant surge tank pressure cap off,
start the engine and let it run until you can
feel the upper radiator hose getting hot. Watch
out for the engine cooling fan.
By this time, the coolant level inside the
coolant surge tank may be lower. If the level is
lower, add more of the proper mixture to the
coolant surge tank until the level reaches
the FULL COLD mark.5. Then replace the pressure cap. Be sure the
pressure cap is hand-tight and fully seated.
6. Verify coolant level after engine is shut off
and the coolant is cold. If necessary, repeat
coolant ll procedure steps 1 through 6.
Engine Fan Noise
Your vehicle has electric cooling fans, you may
hear the fans spinning at low speed during
most everyday driving. The fans may turn off if no
cooling is required. Under heavy vehicle loading,
trailer towing, and/or high outside temperatures, or
if you are operating your air conditioning system,
the fans may change to high speed and you
may hear an increase in fan noise. This is normal
and indicates that the cooling system is
functioning properly. The fans will change to low
speed when additional cooling is no longer
required.
456

Windshield Washer Fluid
What to Use
When you need windshield washer uid, be sure to
read the manufacturer’s instructions before use. If
you will be operating your vehicle in an area where
the temperature may fall below freezing, use a uid
that has sufficient protection against freezing.
Adding Washer Fluid
Your vehicle has a message that comes on when
the washer uid is low. The message is
displayed for 15 seconds at the start of each
ignition cycle. When the CHECK WASHER FLUID
message is displayed, you will need to add
washer uid to the windshield washer uid
reservoir. SeeDIC Warnings and Messages on
page 252for more information.
Open the cap with the
washer symbol on it.
Add washer uid
until the tank is full. See
Engine Compartment
Overview on page 430
for reservoir location.Notice:
When using concentrated washer uid,
follow the manufacturer’s instructions
for adding water.
Do not mix water with ready-to-use washer
uid. Water can cause the solution to
freeze and damage your washer uid tank
and other parts of the washer system.
Also, water does not clean as well
as washer uid.
Fill your washer uid tank only
three-quarters full when it is very cold.
This allows for expansion if freezing
occurs, which could damage the tank if it
is completely full.
Do not use engine coolant (antifreeze) in
your windshield washer. It can damage
your washer system and paint.
458

(g)Inspect system. Check all fuel and vapor
lines and hoses for proper hook-up, routing, and
condition. Check that the purge valve works
properly, if equipped. Replace as needed.
(h)Change automatic transmission uid and lter
if the vehicle is mainly driven under one or
more of these conditions:
In heavy city traffic where the outside
temperature regularly reaches 90°F (32°C)
or higher.
In hilly or mountainous terrain.
When doing frequent trailer towing.
Uses such as found in taxi, police, or delivery
service.
(i)Drain, ush, and rell cooling system. This
service can be complex; you should have
your dealer perform this service. See Engine
Coolant on page 445 for what to use. Inspect
hoses. Clean radiator, condenser, pressure
cap, and ller neck. Pressure test the cooling
system and pressure cap.(j)A uid loss in any vehicle system could indicate
a problem. Have the system inspected and
repaired and the uid level checked. Add uid if
needed.
(k)If you drive regularly under dusty conditions,
inspect the lter at each engine oil change.
(l)Visually inspect belt for fraying, excessive
cracks, or obvious damage. Replace belt if
necessary.
(m)Check vent hose at transfer case for kinks
and proper installation.
Owner Checks and Services
These owner checks and services should be
performed at the intervals specied to help
ensure the safety, dependability, and emission
control performance of your vehicle. Your
GM Goodwrench
®dealer can assist you with
these checks and services.
Be sure any necessary repairs are completed at
once. Whenever any uids or lubricants are added
to your vehicle, make sure they are the proper
ones, as shown inRecommended Fluids and
Lubricants on page 561.
557

Cleaning
Aluminum Wheels.................................... 532
Exterior Lamps/Lenses............................. 531
Fabric/Carpet........................................... 528
Finish Care.............................................. 531
Inside of Your Vehicle.............................. 526
Instrument Panel, Vinyl, and Other Plastic
Surfaces............................................... 529
Leather.................................................... 529
Speaker Covers....................................... 530
Tires........................................................ 533
Underbody Maintenance........................... 534
Washing Your Vehicle.............................. 530
Weatherstrips........................................... 530
Windshield, Backglass, and Wiper
Blades.................................................. 532
Wood Panels........................................... 530
Climate Control System
Dual Automatic......................................... 214
Outlet Adjustment..................................... 222
Rear Air Conditioning and Heating
System, Electronic................................ 223
Collision Damage Repair............................. 583
Comfort Guides, Rear Safety Belt................. 56
Compass..................................................... 158
Content Theft-Deterrent............................... 135Control of a Vehicle..................................... 346
Convenience Net......................................... 180
Coolant
Engine Temperature Gage........................ 236
Heater, Engine......................................... 144
Surge Tank Pressure Cap........................ 448
Cooling System........................................... 451
Cruise Control............................................. 200
Cruise Control Light.................................... 242
Cupholder(s)................................................ 178
Customer Assistance Information
Courtesy Transportation........................... 579
Customer Assistance for Text Telephone
(TTY) Users.......................................... 573
Customer Assistance Offices.................... 574
Customer Satisfaction Procedure.............. 570
GM Mobility Reimbursement Program...... 575
Reporting Safety Defects to General
Motors.................................................. 589
Reporting Safety Defects to the Canadian
Government.......................................... 588
Reporting Safety Defects to the United
States Government............................... 588
Roadside Assistance Program.................. 575
Service Publications Ordering
Information........................................... 589
596