1999 GMC YUKON light

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2-20
Passlock
Your vehicle is equipped with the Passlock
theft
-deterrent system.
Passlock is a passive theft
-deterrent system. Passlock
enables fuel if the ignition lock cylinder is turned with a
valid key. If a correct key is not used or the ignition lock
cylinder is tampered with, fuel is disabled.
During normal operation, the SECURITY light will go
off approximately five seconds after the key is turned to
the RUN ignition position.
If the engine stalls and the SECURITY light flashes,
wait until the light stops flashing before trying to restart
the engine. Remember to release the key from START
as soon as the engine starts.
If the engine is running and the SECURITY light comes
on, you will be able to restart the engine if you turn the
engine off. However, your Passlock system is not working
properly and must be serviced by your dealer. Your vehicle
is not protected by Passlock at this time. You may also
want to check the fuse (see ªFuses and Circuit Breakersº
in the Index). See your dealer for service.
In an emergency, call the GMC Roadside Assistance
Center at 1
-800-GMC-8782 (1-800-462-8782) in the
United States, or 1
-800-268-6800 in Canada.
New Vehicle ªBreak-Inº
NOTICE:
Your vehicle doesn't need an elaborate
ªbreak
-in.º But it will perform better in the long
run if you follow these guidelines:

Keep your speed at 55 mph (88 km/h) or
less for the first 500 miles (805 km).

Don't drive at any one speed
-- fast or
slow
-- for the first 500 miles (805 km).
Don't make full
-throttle starts.

Avoid making hard stops for the first
200 miles (322 km) or so. During this time
your new brake linings aren't yet broken
in. Hard stops with new linings can mean
premature wear and earlier replacement.
Follow this breaking
-in guideline every
time you get new brake linings.

Don't tow a trailer during break
-in. See
ªTowing a Trailerº in the Index for
more information.

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NEUTRAL: Shift the vehicle's transfer case to neutral
only when towing your vehicle. See ªRecreational
Vehicle Towingº or ªTowing Your Vehicleº in the Index
for more information.
Indicator lights in the switches show which setting you
are in. The indicator lights will come on briefly when
you turn on the ignition and one will stay on. If the
lights do not come on, you should take your vehicle to
your dealer for service. An indicator light will flash
while shifting the transfer case. It will remain
illuminated when the shift is complete. If for some
reason the transfer case cannot make a requested shift, it
will return to the last chosen setting.
If the SERVICE 4WD light stays on, you should take
your vehicle to your dealer for service. See ªService
4WDº in the Index for further information.
Shifting to 4HI or AUTO 4WD
Press and release the 4HI or AUTO 4WD switch. This
can be done at any speed, and the indicator light will
flash while shifting. It will remain illuminated when the
shift is completed.
Shifting to 2HI
Press and release the 2HI switch. This can be done at
any speed.Shifting to 4LO
To shift to 4LO, the vehicle's engine must be running and
the vehicle must be stopped or moving less than 3 mph
(4.8 km/h) with the transmission in NEUTRAL (N). The
preferred method for shifting into 4LO is to have your
vehicle moving 1 to 2 mph (1.6 to 3.2 km/h). Press and
release the 4LO switch. You must wait for the 4LO
indicator light to stop flashing and remain illuminated
before shifting your transmission into gear.
If the 4LO switch is pressed when your vehicle is in
gear and/or moving, the 4LO indicator light will flash
for 30 seconds and not complete the shift unless your
vehicle is moving less than 3 mph (4.8 km/h) and the
transmission is in NEUTRAL (N). After 30 seconds the
transfer case will return to the setting last chosen.
Shifting Out of 4LO
To shift from 4LO to 4HI, AUTO 4WD or 2HI your
vehicle must be stopped or moving less than 3 mph
(4.8 km/h) with the transmission in NEUTRAL (N) and
the engine running. The preferred method for shifting
out of 4LO is to have your vehicle moving 1 to 2 mph
(1.6 to 3.2 km/h). Press and release the 4HI, AUTO
4WD or 2HI switch. You must wait for the 4HI, AUTO
4WD or 2HI indicator light to stop flashing and remain
illuminated before shifting your transmission into gear.

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If the 4HI, AUTO 4WD or 2HI switch is pressed when
your vehicle is in gear and/or moving, the 4HI, AUTO
4WD or 2HI indicator light will flash for 30 seconds but
will not complete the shift unless your vehicle is moving
less than 3 mph (4.8 km/h) and the transmission is in
NEUTRAL (N).
Shifting to Neutral
To shift the transfer case to neutral, first make sure the
vehicle is parked so that it will not roll:
1. Set the parking brake.
2. Start the vehicle.
3. Connect the vehicle to the towing vehicle.
4. Put the transmission in NEUTRAL (N).
5. Shift the transfer case to 2HI.
6. Simultaneously press and hold the 2HI and 4LO
buttons for 10 seconds. The red NEUTRAL light
will come on when the transfer case shift to neutral
is complete.7. Shift the transmission to REVERSE (R) for
one second, then shift to AUTOMATIC
OVERDRIVE
for one second.
8. Turn the ignition to OFF.
9. Place the transmission shift lever in PARK (P).
10. Release the parking brake prior to towing.
Shifting Out of Neutral
To shift out of neutral:
1. Set the parking brake and apply the regular brake
pedal.
2. Start the vehicle with the transmission in PARK (P).
3. Press the button for the desired transfer case shift
position (2HI, 4HI, AUTO 4WD or 4LO).
4. Put the transmission in NEUTRAL (N).
5. Shift the transmission lever to the desired position.
After the transfer case has shifted out of NEUTRAL,
the red light will go out.

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Parking Brake
To set the parking brake, hold the regular brake pedal
down with your right foot. Push down the parking brake
pedal with your left foot.
If the ignition is on, the brake system warning light will
come on.
To release the parking
brake, hold the regular
brake pedal down. Pull the
lever, located just above the
parking brake pedal,
marked BRAKE
RELEASE, to release the
parking brake.
If the ignition is on when the parking brake is released,
the brake system warning light will go off.
NOTICE:
Driving with the parking brake on can cause
your rear brakes to overheat. You may have to
replace them, and you could also damage other
parts of your vehicle.
If you are towing a trailer and are parking on any hill,
see ªTowing a Trailerº in the Index. That section shows
what to do first to keep the trailer from moving.

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Locking Rear Axle
Your locking rear axle can give you additional traction
on snow, mud, ice, sand or gravel. It works like a
standard axle most of the time, but when one of the rear
wheels has no traction and the other does, this feature
will allow the wheel with traction to move the vehicle.
Windows
Power Windows
The power window controls are located on each of the
side doors.The driver's door has a switch for the passenger
windows as well. Your power windows will work when
the ignition has been turned to ACCESSORY or RUN or
when Retained Accessory Power (RAP) is present. See
ªRetained Accessory Powerº in the Index.
Push the rear of the switch with the power window
symbol on it to lower the window.
Push the front of the switch with the power window
symbol on it to raise the window.
The driver's window switch has an express
-down
feature that allows the window to be lowered without
holding the switch. Press and hold the side of the
window switch marked AUTO for one second to
activate the express
-down mode. The express-down
mode can be canceled at any time by pressing the
opposite side of the switch. To open the window
partway, lightly tap the switch until the window is at the
desired position.
The power window switch has a lockout feature. This
feature prevents the passenger's windows from
operating except from the driver's position, when the
front driver's side switch is in LOCK. When the switch
is moved to NORM, the rear power windows will
operate again.

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2-41 Headlamp High/Low-Beam Changer
To change the headlamps from low beam to high or high
to low, pull the turn signal lever all the way toward you.
Then release it.
When the high beams are
on, this light on the
instrument panel also
will be on.
Windshield Wipers
You operate the windshield
wipers by turning the
control with the wiper
symbol on it.
For a single wiping cycle, turn the control to MIST.
Hold it there until the wipers start, then let go. Thewipers will stop after one cycle. If you want more
cycles, hold the control on MIST longer.
You can set the wiper speed for a long or short delay
between wipes. This can be very useful in light rain or
snow. Turn the control to choose the delay time. The
closer to LOW, the shorter the delay.
For steady wiping at low speed, turn the control to the
LOW position. For high
-speed wiping, turn the control
further, to HIGH. To stop the wipers, turn the control
to OFF.
Damaged wiper blades may prevent you from seeing
well enough to drive safely. To avoid damage, be sure to
clear ice and snow from the wiper blades before using
them. If they are frozen to the windshield, carefully
loosen or thaw them. If your blades do become
damaged, get new blades or blade inserts.
Heavy snow or ice can overload your wipers. The
windshield wiper motor is protected from overload by a
circuit breaker and a fuse. If the motor overheats due to
heavy snow, etc., the wiper will stop until the motor
cools. Although the circuit is protected from electrical
overload, overload due to heavy snow, etc. may cause
wiper linkage damage. Always clear ice and heavy
snow from the windshield before using your
windshield wipers.

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Reducing Speed While Using Cruise Control
There are two ways to reduce your speed while using
cruise control:

Push in the SET button at the end of the lever until
you reach the lower speed you want, then release it.

To slow down in very small amounts, push the
button for less than half a second. Each time you do
this, you'll go 1 mph (1.6 km/h) slower.
Passing Another Vehicle While Using Cruise Control
Use the accelerator pedal to increase your speed. When
you take your foot off the pedal, your vehicle will slow
down to the cruise control speed you set earlier.
Using Cruise Control on Hills
How well your cruise control will work on hills depends
upon your speed, load and the steepness of the hills.
When going up steep hills, you may have to step on theaccelerator pedal to maintain your speed. If the
steepness of the hill causes the vehicle speed to drop
more than 15 mph (24 km/h) below the set speed, your
cruise control will automatically disengage. When going
downhill, you may have to brake or shift to a lower gear
to keep your speed down. Of course, applying the brake
takes you out of cruise control. Many drivers find this to
be too much trouble and don't use cruise control on
steep hills.
Ending Cruise Control
There are two ways to turn off the cruise control:

Step lightly on the brake pedal or

Move the cruise control switch to OFF.
Erasing Speed Memory
When you turn off the cruise control or the ignition,
your cruise control set speed memory is erased.

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Exterior Lamps
Your parking/headlamp knob is on the driver's side of
your instrument panel.
Turn the knob clockwise, to the parking lamp symbol, to
turn on the following:

Parking Lamps

Sidemarker Lamps
Taillamps

License Plate Lamps

Instrument Panel Lights
Turn the knob clockwise again, to the master lighting
symbol, to turn on all the lamps listed as well as
the headlamps.
Turn the knob counterclockwise, to OFF, to turn off
your lamps. For additional information on headlamp
operation, see ªHeadlamp Delayº in the Index.
Turn the thumbwheel next to the knob up to adjust
instrument panel lights. Turn the thumbwheel up to the
first notch to return the radio display and gearshift
indicator LED display to full intensity when the
headlamps or parking lamps are on. To turn on the dome
lamps (with the vehicle doors closed) turn the
thumbwheel up to the second notch position.
You can switch your headlamps from high to low beam
by pulling on the turn signal/high
-beam lever.
A circuit breaker protects your headlamps. If you have
an electrical overload, your headlamps will flicker on
and off. Have your headlamp wiring checked right away
if this happens.