automatic transmission GMC YUKON 2007 User Guide

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

A. Engine Air Cleaner/Filter. SeeEngine
Air Cleaner/Filter on page 437.
B. Air Filter Restriction Indicator (If Equipped).
SeeEngine Air Cleaner/Filter on page 437.
C. Coolant Surge Tank and Pressure Cap.
SeeCooling System on page 451andCoolant
Surge Tank Pressure Cap on page 448.
D. Remote Positive (+) Terminal. SeeJump
Starting on page 464.
E. Battery. SeeBattery on page 463.
F. Engine Oil Fill Cap. See “When to Add Engine
Oil” underEngine Oil on page 432.
G. Automatic Transmission Dipstick (Out of View).
See “Checking the Fluid Level” under
Automatic Transmission Fluid on page 440.H. Remote Negative (−) Terminal (GND) (Out of
View). SeeJump Starting on page 464.
I. Engine Oil Dipstick (Out of View). See
“Checking Engine Oil” underEngine Oil on
page 432.
J. Engine Cooling Fan (Out of View). SeeCooling
System on page 451.
K. Power Steering Fluid Reservoir (Out of View).
SeePower Steering Fluid on page 457.
L. Brake Master Cylinder Reservoir. See “Brake
Fluid” underBrakes on page 459.
M. Underhood Fuse Block. SeeUnderhood Fuse
Block on page 541.
N. Windshield Washer Fluid Reservoir. See
“Adding Washer Fluid” underWindshield
Washer Fluid on page 458.
431

5. Inspect or replace the engine air cleaner/lter.
6. Reinstall the cover and tighten the screws.
7. Reset the air lter restriction indicator, if
the vehicle has one, by pressing the top button
on the indicator.
{CAUTION:
Operating the engine with the air
cleaner/lter off can cause you or others
to be burned. The air cleaner not only
cleans the air; it helps to stop ames if
the engine backres. If it is not there and
the engine backres, you could be
burned. Do not drive with it off, and be
careful working on the engine with the air
cleaner/lter off.
Automatic Transmission Fluid
When to Check and Change Automatic
Transmission Fluid
It is usually not necessary to check the
transmission uid level. A transmission uid leak
is the only reason for uid loss. If you suspect
a small leak, then use the following checking
procedures to check the uid level. However, if
there is a large leak, then it may be necessary to
have the vehicle towed to a dealership service
department and have it repaired before driving the
vehicle further.
Notice:Use of the incorrect automatic
transmission uid may damage your vehicle,
and the damages may not be covered by
your warranty. Always use the automatic
transmission uid listed inRecommended
Fluids and Lubricants on page 561.
Change the uid and lter at the intervals listed in
the Maintenance Schedule. SeeScheduled
Maintenance on page 551. Be sure to use the
transmission uid listed inRecommended Fluids
and Lubricants on page 561.
440

How to Check Automatic
Transmission Fluid
Notice:Too much or too little uid can
damage your transmission. Too much can
mean that some of the uid could come out
and fall on hot engine parts or exhaust system
parts, starting a re. Too little uid could
cause the transmission to overheat. Be sure to
get an accurate reading if you check your
transmission uid.
Before checking the uid level, prepare your
vehicle as follows:
1. Start the engine and park your vehicle on a
level surface. Keep the engine running.
2. Apply the parking brake and place the shift
lever in PARK (P).
3. With your foot on the brake pedal, move the
shift lever through each gear range, pausing
for about three seconds in each range.
Then, move the shift lever back to PARK (P).4. Allow the engine to idle (500 – 800 rpm)
for at least one minute. Slowly release the
brake pedal.
5. Keep the engine running and press the
Trip/Fuel button until TRANS TEMP
(Transmission Temperature) displays on the
Driver Information Center (DIC).
6. Using the TRANS TEMP reading, determine
and perform the appropriate check procedure.
If the TRANS TEMP reading is not within
the required temperature ranges, allow
the vehicle to cool, or operate the vehicle until
the appropriate transmission uid temperature
is reached.
441

To avoid the possibility of the vehicles rolling,
set the parking brake rmly on both vehicles
involved in the jump start procedure. Put
the automatic transmission in PARK (P) or a
manual transmission in NEUTRAL before
setting the parking brake. If you have a
four-wheel-drive vehicle, be sure the transfer
case is in a drive gear, not in NEUTRAL.
Notice:If you leave your radio or other
accessories on during the jump starting
procedure, they could be damaged. The repairs
would not be covered by your warranty.
Always turn off your radio and other
accessories when jump starting your vehicle.
3. Turn off the ignition on both vehicles.
Unplug unnecessary accessories plugged
into the cigarette lighter or the accessory
power outlets. Turn off the radio and all the
lamps that are not needed. This will avoid
sparks and help save both batteries. And it
could save the radio!4. Open the hood on the other vehicle and
locate the positive (+) and negative (−)
terminal locations on that vehicle.
Your vehicle has a remote positive (+) jump
starting terminal and a remote negative (−)
jump starting terminal. You should always use
these remote terminals instead of the
terminals on the battery.
The remote positive (+) terminal, if equipped, is
located under a red plastic cover at the positive
battery post. To uncover the remote positive (+)
terminal, open the red plastic cover.
The remote negative (−) terminal is a stud
located on the right front of the engine, where
the negative battery cable attaches.
465