parking brake GMC YUKON DENALI 2007 User Guide

A trailer was attached to your vehicle, or a
bicycle or an object was hanging out of your
trunk during your last drive when you turned off
the vehicle. If the attached objects are removed
from your vehicle before the start of your next
drive, the system will return to normal operation
unless an object is detected when the vehicle is
shifted into REVERSE (R). If this occurs, URPA
assumes the object is still attached, so you will
have to wait until the vehicle is driven forward
above 15 mph (25 km/h) before URPA will
return to normal operation.
The ultrasonic sensors are not kept clean. So,
be sure to keep your vehicle’s rear bumper free
of mud, dirt, snow, ice, and slush. For cleaning
instructions, seeWashing Your Vehicle on
page 530. If the DIC still displays the PARKING
ASSIST OFF message after cleaning the
bumper and driving forward at a speed of at
least 15 mph (25 km/h), see your dealer.
Other conditions that may affect system
performance include vibrations from a
jackhammer or the compression of air brakes
on a very large truck or other mechanical
devices that interfere with URPA performance.
When URPA is disabled without driver action
and the driver attempts to turn URPA back on
using the Driver Information Center (DIC), the
PARKING ASSIST ON option will not be
selectable if the necessary conditions stated
above for normal system operation are not met.
As always, drivers should use care when backing
up a vehicle. Always look behind you, being
sure to check for other vehicles, obstructions and
blind spots.
For Driver Information Center messages related
to URPA, seeDIC Warnings and Messages
on page 252.
If the bumper is damaged, your URPA system
may not work properly. Take the vehicle to
your dealer to repair the system.
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Readings in the low warning zone may occur
when a large number of electrical accessories are
operating in the vehicle and the engine is left at
an idle for an extended period. This condition
is normal since the charging system is not able to
provide full power at engine idle. As engine
speeds are increased, this condition should correct
itself as higher engine speeds allow the charging
system to create maximum power.
You can only drive for a short time with the
reading in either warning zone. If you must drive,
turn off all unnecessary accessories.
Readings in either warning zone indicate a
possible problem in the electrical system. Have
the vehicle serviced as soon as possible.Brake System Warning Light
With the ignition on, the brake system warning
light will come on when you set the parking brake.
If you try to drive with the parking brake engaged,
a chime will sound when the vehicle speed is
greater than 3 mph (5 km/h).
Your vehicle’s hydraulic brake system is divided
into two parts. If one part is not working, the other
part can still work and stop you. For good
braking, though, you need both parts working well.
If the warning light comes on and a chime
sounds there could be a brake problem. Have
your brake system inspected right away.
This light may also come on due to low brake
uid. SeeBrakes on page 459for more
information.
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SERVICE BRAKES SOON
If there is a problem with the brake system, this
message will display. If this message appears,
stop as soon as possible and turn off the vehicle.
Restart the vehicle and check for the message
on the DIC display. If the message is still displayed
or appears again when you begin driving, the
brake system needs service. See your dealer.
SERVICE PARK ASSIST
This message will display if there is a problem
with the Ultrasonic Rear Parking Assist (URPA)
system. Do not use this system to help you park.
SeeUltrasonic Rear Parking Assist (URPA) on
page 208for more information. See your dealer for
service.
SERVICE STABILITRAK
If your vehicle has StabiliTrak®and this message
displays, it means there may be a problem
with the StabiliTrak
®system. If you see this
message, try to reset the system. Stop; turn off
the engine for at least 15 seconds; then start
the engine again. If this message still comes on, it
means there is a problem. You should see your
dealer for service. The vehicle is safe to drive,
however, you do not have the benet of
StabiliTrak
®, so reduce your speed and drive
accordingly.
SERVICE SUSPENSION SYSTEM
If your vehicle has the Autoride®suspension
system, this message will display when the
Autoride
®suspension system is not operating
properly. Have your vehicle serviced by your
dealer.
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Here are some ways in which you can help avoid
distraction while driving.
While your vehicle is parked:
Familiarize yourself with all of its controls.
Familiarize yourself with its operation.
Set up your audio system by presetting your
favorite radio stations, setting the tone, and
adjusting the speakers. Then, when driving
conditions permit, you can tune to your favorite
radio stations using the presets and steering
wheel controls if the vehicle has them.
Notice:Before adding any sound equipment
to your vehicle, such as an audio system,
CD player, CB radio, mobile telephone,
or two-way radio, make sure that it can be
added by checking with your dealer. Also,
check federal rules covering mobile radio and
telephone units. If sound equipment can be
added, it is very important to do it properly.
Added sound equipment may interfere with the
operation of your vehicle’s engine, radio, or
other systems, and even damage them.
Your vehicle’s systems may interfere with the
operation of sound equipment that has
been added.Notice:The chime signals related to safety
belts, parking brake, and other functions
of your vehicle operate through the
radio/entertainment system. If that equipment
is replaced or additional equipment is added
to your vehicle, the chimes may not work. Make
sure that replacement or additional equipment
is compatible with your vehicle before
installing it. SeeAccessories and Modifications
on page 421.
Your vehicle may have a feature called Retained
Accessory Power (RAP). With RAP, the audio
system can be played even after the ignition
is turned off. SeeRetained Accessory Power
(RAP) on page 141for more information.
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{CAUTION:
Turning or driving across steep hills can
be dangerous. You could lose traction,
slide sideways, and possibly roll over.
You could be seriously injured or killed.
When driving up hills, always try to go
straight up.
Ease up on your speed as you approach the
top of the hill.
Attach a ag to the vehicle to make you more
visible to approaching traffic on trails or hills.
Sound the horn as you approach the top of the
hill to let opposing traffic know you are there.
Use your headlamps even during the day. They
make you more visible to oncoming traffic.
{CAUTION:
Driving to the top (crest) of a hill at full
speed can cause an accident. There could
be a drop-off, embankment, cliff, or even
another vehicle. You could be seriously
injured or killed. As you near the top of a
hill, slow down and stay alert.
Q:What should I do if my vehicle stalls, or
is about to stall, and I cannot make it up
the hill?
A:If this happens, there are some things you
should do and there are some things you
must not do. First, here is what youshoulddo:
Push the brake pedal to stop the vehicle
and keep it from rolling backwards. Also, apply
the parking brake.
If the engine is still running, shift the
transmission to REVERSE (R), release the
parking brake, and slowly back down the
hill as straight as possible in REVERSE (R).
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As you are backing down the hill, put your left
hand on the steering wheel at the 12 o’clock
position. This way, you will be able to tell if the
wheels are straight and maneuver as you
back down. It is best that you back down the
hill with the wheels straight rather than in
the left or right direction. Turning the wheel
too far to the left or right will increase the
possibility of a rollover.
Here are some things youmust notdo if you stall,
or are about to stall, when going up a hill.
Never attempt to prevent a stall by shifting
into NEUTRAL (N) to rev-up the engine
and regain forward momentum. This will
not work. Your vehicle will roll backwards
very quickly and you could go out of control.
Instead, apply the regular brake to stop
the vehicle. Then apply the parking brake.
Shift to REVERSE (R), release the parking
brake, and slowly back straight down.
Never attempt to turn around if you are about
to stall when going up a hill. If the hill is steep
enough to stall your vehicle, it is steep
enough to cause you to roll over if you turn
around. If you cannot make it up the hill, you
must back straight down the hill.
Q:Suppose, after stalling, I try to back down
the hill and decide I just cannot do it. What
should I do?
A:Set the parking brake, put the transmission in
PARK (P) and turn off the engine. Leave the
vehicle and go get some help. Exit on the
uphill side and stay clear of the path the
vehicle would take if it rolled downhill.
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?
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Q:Am I likely to stall when going downhill?
A:It is much more likely to happen going
uphill. But if it happens going downhill, here is
what to do.
1. Stop your vehicle by applying the regular
brakes. Apply the parking brake.
2. Shift to PARK (P) and, while still braking,
restart the engine.
3. Shift back to a low gear, release the parking
brake, and drive straight down.
4. If the engine will not start, get out and
get help.
Driving Across an Incline
Sooner or later, an off-road trail will probably go
across the incline of a hill. If this happens,
you have to decide whether to try to drive across
the incline. Here are some things to consider:
A hill that can be driven straight up or
down may be too steep to drive across. When
you go straight up or down a hill, the length
of the wheel base — the distance from
the front wheels to the rear wheels — reduces
the likelihood the vehicle will tumble end
over end. But when you drive across
an incline, the much more narrow track
width — the distance between the left and
right wheels — may not prevent the vehicle
from tilting and rolling over. Also, driving
across an incline puts more weight on
the downhill wheels. This could cause a
downhill slide or a rollover.
Surface conditions can be a problem when
you drive across a hill. Loose gravel, muddy
spots, or even wet grass can cause your tires
to slip sideways, downhill. If the vehicle
slips sideways, it can hit something that will
trip it — a rock, a rut, etc. — and roll over.
370

Parking on Hills
{CAUTION:
You really should not park your vehicle,
with a trailer attached, on a hill. If
something goes wrong, your rig could
start to move. People can be injured, and
both your vehicle and the trailer can be
damaged.But if you ever have to park your rig on a hill,
here’s how to do it:
1. Apply your regular brakes, but don’t shift into
PARK (P) yet.
2. Have someone place chocks under the trailer
wheels.
3. When the wheel chocks are in place, release
the regular brakes until the chocks absorb
the load.
4. Reapply the regular brakes. Then apply your
parking brake and shift into PARK (P).
5. Release the regular brakes.
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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

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.
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