2007 GMC YUKON XL DENALI automatic transmission

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 153.
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).
Shifting Out of Park (P)
Your vehicle has an automatic transmission shift
lock control system which locks the shift lever
in PARK (P) when the ignition is in the LOCK.
You have to fully apply your regular brakes before
you can shift from PARK (P) when the ignition
is in RUN. SeeAutomatic Transmission Operation
on page 145.
If you cannot shift out of PARK (P), ease pressure
on the shift lever and push the shift lever all the
way up into PARK (P) as you maintain brake
application. Then, move the shift lever into
the desired gear.
154

A. Air Outlets. SeeOutlet Adjustment on
page 222.
B. Turn Signal/Multifunction Lever. SeeTurn
Signal/Multifunction Lever on page 193.
C. Instrument Panel Cluster. SeeInstrument Panel
Cluster on page 226.
D. Gearshift Lever. SeeAutomatic Transmission
Operation on page 145.
E. Tow/Haul Selector Button. SeeTow/Haul Mode
on page 150.
F. Driver Information Center Controls. SeeDriver
Information Center (DIC) on page 244.
G. Audio System. SeeAudio System(s) on
page 272.
H. Exterior Lamps Control. SeeExterior Lamps on
page 203.
I. Dome Lamp Override Button. SeeDome Lamp
Override on page 207.J. Cruise Control Buttons. SeeAudio Steering
Wheel Controls on page 335.
K. Tilt Wheel Lever. SeeTilt Wheel on page 193.
L. Horn. SeeHorn on page 192.
M. Audio Steering Wheel Controls. SeeAudio
Steering Wheel Controls on page 335.
N. Dual Automatic Climate Controls. SeeDual
Automatic Climate Control System on
page 214.
O. Accessory Power Outlets. SeeAccessory
Power Outlet(s) on page 213. Cigarette Lighter
(If Equipped). SeeAshtray(s) and Cigarette
Lighter on page 214.
P. StabiliTrak
®Button. SeeStabiliTrak®System
on page 349. Rear Park Aid Disable Button.
SeeUltrasonic Rear Parking Assist (URPA) on
page 208.
Q. Glovebox. SeeGlove Box on page 178.
191

Timer
Press the trip/fuel button until TIMER displays.
This display can be used as a timer.
To start the timer, press the set/reset button while
TIMER is displayed. The display will show the
amount of time that has passed since the timer was
last reset, not including time the ignition is off. Time
will continue to be counted as long as the ignition is
on, even if another display is being shown on the
DIC. The timer will record up to 99 hours,
59 minutes and 59 seconds (99:59:59) after which
the display will return to zero.
To stop the timer, press the set/reset button briey
while TIMER is displayed.
To reset the timer to zero, press and hold the
set/reset button while TIMER is displayed.
Transmission Temperature
Press the trip/fuel button until TRANS TEMP
displays. This display shows the temperature of
the automatic transmission uid in either degrees
Fahrenheit (°F) or degrees Celsius (°C).
Blank Display
This display shows no information.
Vehicle Information Menu Items
T
(Vehicle Information):Press this button to
scroll through the following menu items:
Oil Life
Press the vehicle information button until OIL LIFE
REMAINING displays. This display shows an
estimate of the oil’s remaining useful life. If you see
99% OIL LIFE REMAINING on the display, that
means 99% of the current oil life remains. The
engine oil life system will alert you to change your
oil on a schedule consistent with your driving
conditions.
When the remaining oil life is low, the CHANGE
ENGINE OIL SOON message will appear on the
display. See “CHANGE ENGINE OIL SOON” under
DIC Warnings and Messages on page 252. You
should change your oil as soon as you can. See
Engine Oil on page 432. In addition to the engine oil
life system monitoring the oil life, additional
maintenance is recommended in the Maintenance
Schedule in this manual. SeeScheduled
Maintenance on page 551for more information.
248

Traction Control Operation
The traction control system is part of the
StabiliTrak®system. Traction control limits wheel
spin by reducing engine power to the wheels
(engine speed management) and by applying
brakes to each individual wheel (brake-traction
control) as necessary.
The traction control system is enabled
automatically when you start your vehicle. It will
activate and the StabiliTrak
®light will ash if
it senses that any of the wheels are spinning or
beginning to lose traction while driving. If you turn
off traction control, only the brake-traction
control portion of traction control will work. The
engine speed management will be disabled. In this
mode, engine power is not reduced automatically
and the driven wheels can spin more freely.
This can cause the brake-traction control to
activate constantly.
Notice:If you allow the wheel(s) of one axle
to spin excessively while the StabiliTrak
®, ABS
and brake warning lights and the SERVICE
STABILITRAK message are displayed,
you could damage the transfer case. The
repairs would not be covered by your warranty.Reduce engine power and do not spin the
wheel(s) excessively while these lights and this
message are displayed.
The traction control system may activate on
dry or rough roads or under conditions such as
heavy acceleration while turning or abrupt
upshifts/downshifts of the transmission. When
this happens, you may notice a reduction in
acceleration, or may hear a noise or vibration.
This is normal.
If your vehicle is in cruise control when the system
activates, the StabiliTrak
®light will ash and the
cruise control will automatically disengage.
When road conditions allow you to use cruise
again, you may re-engage the cruise control. See
Cruise Control on page 200.
StabiliTrak
®may also turn off automatically if it
determines that a problem exists with the system.
If the problem does not clear itself after restarting
the vehicle, you should see your dealer for
service.
352

Press this button at the end of the shift lever to
enable tow/haul mode.
When the button is pressed, a light on the
instrument panel will illuminate to indicate that
Tow/Haul has been selected. Tow/Haul may
be turned off by pressing the button again, at
which time the indicator light on the instrument
panel will turn off. The vehicle will automatically
turn off tow/haul every time it is started.Tow/Haul is designed to be most effective
when the vehicle and trailer combined weight
is at least 75 percent of the vehicle’s Gross
Combination Weight Rating (GCWR). See “Weight
of the Trailer” later in this section. Tow/Haul is
most useful under the following driving conditions:
When pulling a heavy trailer or a large or
heavy load through rolling terrain.
When pulling a heavy trailer or a large or
heavy load in stop and go traffic.
When pulling a heavy trailer or a large or
heavy load in busy parking lots where
improved low speed control of the vehicle is
desired.
Operating the vehicle in Tow/Haul when lightly
loaded or with no trailer at all will not cause
damage. However, there is no benet to the
selection of Tow/Haul when the vehicle is
unloaded. Such a selection when unloaded may
result in unpleasant engine and transmission
driving characteristics and reduced fuel economy.
Tow/Haul is recommended only when pulling a
heavy trailer or a large or heavy load.
402

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

When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal
down while you:
start your engine,
shift into a gear, and
release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the
chocks.
4. Stop and have someone pick up and store the
chocks.
Maintenance When Trailer Towing
Your vehicle will need service more often when
you’re pulling a trailer. See the Maintenance
Schedule for more on this. Things that are
especially important in trailer operation are
automatic transmission uid (don’t overll), engine
oil, axle lubricant, belts, cooling system and
brake system. Each of these is covered in this
manual, and the Index will help you nd them
quickly. If you’re trailering, it’s a good idea
to review these sections before you start your trip.
Check periodically to see that all hitch nuts and
bolts are tight.
413

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