2007 GMC YUKON XL DENALI ECU

If you put things inside your vehicle – like
suitcases, tools, packages, or anything else – they
go as fast as the vehicle goes. If you have to
stop or turn quickly, or if there is a crash, they’ll
keep going.
{CAUTION:
Things you put inside your vehicle can
strike and injure people in a sudden stop
or turn, or in a crash.
Put things in the cargo area of your
vehicle. Try to spread the weight
evenly.
Never stack heavier things, like
suitcases, inside the vehicle so that
some of them are above the tops of
the seats.
Do not leave an unsecured child
restraint in your vehicle.
When you carry something inside the
vehicle, secure it whenever you can.
Do not leave a seat folded down
unless you need to.There’s also important loading information for
off-road driving in this manual. See “Loading Your
Vehicle for Off-Road Driving” underOff-Road
Driving on page 359.
Automatic Level Control
The automatic level control rear suspension
comes as a part of the Autoride®suspension. See
Autoride®on page 399.
This type of level control is fully automatic and will
provide a better leveled riding position as well
as better handling under a variety of passenger
and loading conditions. An air compressor
connected to the rear shocks will raise or lower
the rear of the vehicle to maintain proper vehicle
height. The system is activated when the
ignition key is turned to RUN and will automatically
adjust vehicle height thereafter. The system
may exhaust (lower vehicle height) for up to
10 minutes after the ignition key has been turned
to OFF. You may hear the air compressor
operating when the height is being adjusted.
If a weight-distributing hitch is being used, it is
recommended to allow the shocks to inate,
thereby leveling the vehicle prior to adjusting the
height.
397

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.
Following Distance
Stay at least twice as far behind the vehicle ahead
as you would when driving your vehicle without
a trailer. This can help you avoid situations
that require heavy braking and sudden turns.
Passing
You’ll need more passing distance up ahead when
you’re towing a trailer. And, because you’re a
good deal longer, you’ll need to go much farther
beyond the passed vehicle before you can
return to your lane.
Backing Up
Hold the bottom of the steering wheel with
one hand. Then, to move the trailer to the left, just
move that hand to the left. To move the trailer
to the right, move your hand to the right. Always
back up slowly and, if possible, have someone
guide you.
Making Turns
Notice:Making very sharp turns while
trailering could cause the trailer to come in
contact with the vehicle. Your vehicle could
be damaged. Avoid making very sharp
turns while trailering.
When you’re turning with a trailer, make wider
turns than normal. Do this so your trailer
won’t strike soft shoulders, curbs, road signs,
trees or other objects. Avoid jerky or sudden
maneuvers. Signal well in advance.
410

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

Tire Inspection and Rotation
Tires should be rotated every 5,000 to 8,000 miles
(8 000 to 13 000 km).
Any time you notice unusual wear, rotate your
tires as soon as possible and check wheel
alignment. Also check for damaged tires or wheels.
SeeWhen It Is Time for New Tires on page 497
andWheel Replacement on page 503for
more information.
Make sure the spare tire is stored securely.
Push, pull, and then try to rotate or turn the tire.
If it moves, use the ratchet/wheel wrench to tighten
the cable. SeeChanging a Flat Tire on page 506.
The purpose of regular rotation is to achieve
more uniform wear for all tires on the vehicle.
The rst rotation is the most important. See
Scheduled Maintenance on page 551.When rotating your vehicle’s tires, always use the
correct rotation pattern shown here.
Do not include the spare tire in the tire rotation.
After the tires have been rotated, adjust the
front and rear ination pressures as shown on the
tire and loading information label. SeeLoading
Your Vehicle on page 392andInation - Tire
Pressure on page 488, for more information.
496

4. Repeat this procedure at least two times.
If the spare tire lowers to the ground,
continue with Step 5 ofRemoving the
Spare Tire and Tools on page 507.
5. If the spare tire does not lower, turn the wheel
wrench counterclockwise until approximately
6 inches (15 cm) of cable is exposed.
6. Stand the wheel blocks on their shortest ends,
with the backs facing each other.
7. Place the bottom
edge of the jack (A)
on the wheel
blocks (B),
separating them so
that the jack is
balanced securely.8. Attach the jack handle, extension, and wheel
wrench to the jack and place it (with the
wheel blocks) under the vehicle toward the
front of the rear bumper.
519

4. Insert the open end
of the extension (J)
through the hole
in the rear
bumper (I) (hoist
shaft access hole).
5. Raise the tire part way upward. Make sure the
retainer is seated in the wheel opening.
6. Raise the tire fully against the underside of
the vehicle by turning the wheel wrench
clockwise until you hear two clicks or feel it
skip twice. You cannot overtighten the cable.7. Make sure the tire is stored securely. Push,
pull (A), and then try to turn (B) the tire. If the
tire moves, use the wheel wrench to tighten
the cable.
8. Reinstall the spare tire lock.
9. Reinstall the hoist shaft access cover.
10. Reinstall the hitch cover.
524

To store the tools, do the following.
A. Wheel Blocks
B. Tool Bag with Jack
Tools
C. Retaining Bracket
D. Wing Nut Retaining
Tool BagE. Jack
F. Wing Nut Retaining
Wheel Blocks
G. Wing Nut on Jack
1. Return the tools (wheel wrench, jack handle,
and jack handle extensions) to the tool bag (B).
2. Assemble wheel blocks (A) and jack (E)
together with the wing nut (F).3. Position the jack (E) and wheel blocks (A) in the
driver’s side trim panel over the wheelhouse.
4. Turn the wing nut (G) clockwise until the jack
is secured tight in the mounting bracket. Be
sure to position the holes in the base of
the jack onto the pin in the mounting bracket.
5. Use the retaining bracket (C) to fasten the tool
bag (B) on the stud and turn the wing nut (D)
clockwise to secure.
6. Return the storage tray to its original stored
position.
Regular Wheelbase shown,
Extended Wheelbase similar.
525

At Each Fuel Fill
It is important to perform these underhood checks
at each fuel ll.
Engine Oil Level Check
Check the engine oil level and add the proper
oil if necessary. SeeEngine Oil on page 432for
further details.
Notice:It is important to check your oil
regularly and keep it at the proper level. Failure
to keep your engine oil at the proper level
can cause damage to your engine not covered
by your warranty.
Engine Coolant Level Check
Check the engine coolant level and add
DEX-COOL®coolant mixture if necessary. See
Engine Coolant on page 445for further details.
Windshield Washer Fluid Level Check
Check the windshield washer uid level in
the windshield washer uid reservoir and add the
proper uid if necessary.
At Least Once a Month
Tire Ination Check
Visually inspect your vehicle’s tires and make sure
they are inated to the correct pressures. Do
not forget to check the spare tire. SeeTires on
page 480for further details. Check to make
sure the spare tire is stored securely. See
Changing a Flat Tire on page 506.
Tire Wear Inspection
Tire rotation may be required for high mileage
highway drivers prior to the Engine Oil Life System
service notication. Check the tires for wear
and, if necessary, rotate the tires. SeeTire
Inspection and Rotation on page 496.
558