engine overheat GMC YUKON XL 2007 Owners Manual

Retained Accessory Power (RAP)
Your vehicle has a Retained Accessory Power
(RAP) feature which will allow certain features on
your vehicle to continue to work up to 10 minutes
after the ignition key is turned to LOCK.
The radio, power windows, and if the vehicle
has these features, the sunroof and OnStar
®
System, will work when the ignition key is in
RUN or ACCESSORY. Once the key is turned
from RUN to LOCK, these features will continue
to work for up to 10 minutes or until a door is
opened.
Starting the Engine
Move your shift lever to PARK (P) or
NEUTRAL (N). Your engine will not start in
any other position — that is a safety feature.
To restart when you are already moving, use
NEUTRAL (N) only.
Notice:Do not try to shift to PARK (P) if
your vehicle is moving. If you do, you could
damage the transmission. Shift to PARK (P)
only when your vehicle is stopped.1. With your foot off the accelerator pedal, turn
the ignition key to START. When the engine
starts, let go of the key. The idle speed will go
down as your engine gets warm.
Your vehicle has a Computer-Controlled
Cranking System. This feature assists in
starting the engine and protects the electrical
system. If the ignition key is turned to the
START position, and then released when the
engine begins cranking, the engine will continue
cranking until the vehicle starts or until it
exceeds the maximum cranking time allowed,
approximately 15 seconds to prevent cranking
motor damage. To prevent gear damage, this
system also prevents cranking if the engine is
already running. The engine cranking can be
stopped by turning the ignition switch to the
ACCESSORY or LOCK position.
Notice:Cranking the engine for long periods of
time, by returning the key to the START position
immediately after cranking has ended, can
overheat and damage the cranking motor and
drain the battery. Waiting about 15 seconds
between each try, to allow the cranking motor to
cool down, will prevent damage due to
overheating.
138

To Use the Engine Coolant Heater
1. Turn off the engine.
2. Open the hood and unwrap the electrical
cord. The cord is located on the driver’s
side of the engine compartment, near
the power steering uid reservoir.
3. Plug the cord into a normal, grounded
110-volt AC outlet.
{CAUTION:
Plugging the cord into an ungrounded
outlet could cause an electrical shock.
Also, the wrong kind of extension cord
could overheat and cause a re. 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.
How long should you keep the coolant heater
plugged in? The answer depends on the outside
temperature, the kind of oil you have, and some
other things. Instead of trying to list everything here,
we ask that you contact your dealer in the area
where you will be parking your vehicle. The dealer
can give you the best advice for that particular area.
Displacement on Demand™ (DoD™)
Your vehicle’s V8 engine may have Displacement
on Demand™ (DoD™). This system allows the
engine to operate on either all or half of its
cylinders, depending on your driving conditions.
When less power is required, such as cruising at a
constant vehicle speed, the system will operate in
the half cylinder mode, allowing your vehicle to
achieve better fuel economy. When greater power
demands are required, such as accelerating from a
stop, passing, or merging onto a freeway, the
system will maintain full-cylinder operation.
141

CAUTION: (Continued)
If you have four-wheel drive and your
transfer case is in NEUTRAL, your vehicle
will be free to roll, even if your shift lever
is in PARK (P). So be sure the transfer
case is in a drive gear — not in NEUTRAL.
And, if you leave the vehicle with the
engine running, it could overheat and
even catch re. You or others could be
injured. Do not leave your vehicle with the
engine running unless you have to.
If you have to leave your vehicle with the engine
running, be sure your vehicle is in PARK (P)
and the parking brake is rmly set before
you leave it. After you move the shift lever into
PARK (P), hold the regular brake pedal down.
Then, see if you can move the shift lever away
from PARK (P) without rst pulling it toward you.
If you can, it means that the shift lever was
not fully locked into PARK (P).
Torque Lock
If you are parking on a hill and you do not shift your
transmission into PARK (P) properly, the weight of
the vehicle may put too much force on the parking
pawl in the transmission. You may nd it difficult to
pull the shift lever out of PARK (P). This is called
“torque lock.” To prevent torque lock, set the
parking brake and then shift into PARK (P) properly
before you leave the driver’s seat. To nd out how,
seeShifting Into Park (P) on page 152.
When you are ready to drive, move the shift lever
out of PARK (P) before you release the parking
brake.
If torque lock does occur, you may need to have
another vehicle push yours a little uphill to
take some of the pressure from the parking pawl
in the transmission, then you will be able to
pull the shift lever out of PARK (P).
153

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 Downhill
When off-roading takes you downhill, you will want
to consider a number of things:
How steep is the downhill? Will I be able to
maintain vehicle control?
What is the surface like? Smooth? Rough?
Slippery? Hard-packed dirt? Gravel?
Are there hidden surface obstacles? Ruts?
Logs? Boulders?
What is at the bottom of the hill? Is there a
hidden creek bank or even a river bottom
with large rocks?
If you decide you can go down a hill safely, then
try to keep your vehicle headed straight down, and
use a low gear. This way, engine drag can help
your brakes and they will not have to do all
the work. Descend slowly, keeping your vehicle
under control at all times.
{CAUTION:
Heavy braking when going down a hill can
cause your brakes to overheat and fade.
This could cause loss of control and a
serious accident. Apply the brakes lightly
when descending a hill and use a low
gear to keep vehicle speed under control.
Q:Are there some things I should not do
when driving down a hill?
A:Yes! These are important because if you
ignore them you could lose control and
have a serious accident.
When driving downhill, avoid turns that take
you across the incline of the hill. A hill that
is not too steep to drive down may be
too steep to drive across. You could roll over
if you do not drive straight down.
Never go downhill with the transmission in
NEUTRAL (N). This is called “free-wheeling.”
Your brakes will have to do all the work
and could overheat and fade.
367

If Your Vehicle is Stuck in Sand,
Mud, Ice, or Snow
In order to free your vehicle when it is stuck, you
will need to spin the wheels, but you do not
want to spin your wheels too fast. The method
known as rocking can help you get out when you
are stuck, but you must use caution.
{CAUTION:
If you let your tires spin at high speed,
they can explode, and you or others could
be injured. And, the transmission or other
parts of the vehicle can overheat. That
could cause an engine compartment re
or other damage. When you are stuck,
spin the wheels as little as possible.
Do not spin the wheels above 35 mph
(55 km/h) as shown on the speedometer.Notice:Spinning your wheels can destroy
parts of your vehicle as well as the tires. If you
spin the wheels too fast while shifting your
transmission back and forth, you can destroy
your transmission.
For more information about using tire chains on
your vehicle, seeTire Chains on page 506.
Rocking Your Vehicle to Get It Out
First, turn your steering wheel left and right. That
will clear the area around your front wheels. If you
have a four-wheel-drive vehicle, shift into
Four-Wheel High or Four-Wheel Low. Turn the
StabiliTrak
®System off. SeeStabiliTrak®System
on page 348. Then shift back and forth between
REVERSE (R) and a forward gear, spinning the
wheels as little as possible. Release the accelerator
pedal while you shift, and press lightly on the
accelerator pedal when the transmission is in gear.
By slowly spinning your wheels in the forward and
reverse directions, you will cause a rocking motion
that may free your vehicle. If that does not get you
out after a few tries, you may need to be towed out.
Or, you can use your recovery hooks if your vehicle
has them. If you do need to be towed out, see
Towing Your Vehicle on page 400.
388