1999 GMC YUKON automatic transmission

2-
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Section 2 Features and Controls
Here you can learn about the many standard and optional features on your vehicle, and information on starting,
shifting and braking. Also explained are the instrument panel and the warning systems that tell you if everything is
working properly
-- and what to do if you have a problem.
2
-2 Keys
2
-3 Door Locks
2
-6 Keyless Entry System
2
-11 Rear Doors
2
-13 Theft
2
-13 Theft-Deterrent System
2
-16 Feature Customization
2
-20 Passlock

2-20 New Vehicle ªBreak-Inº
2
-21 Ignition Positions
2
-22 Starting Your Engine
2
-24 Engine Coolant Heater (If Equipped)
2
-25 Automatic Transmission Operation
2
-28 Four-Wheel Drive
2
-32 Parking Brake
2
-33 Shifting Into Park (P)
2
-35 Shifting Out of Park (P)
2
-36 Parking Over Things That Burn
2
-36 Engine Exhaust2
-37 Running Your Engine While You're Parked
2
-38 Locking Rear Axle
2
-38 Windows
2
-39 Horn
2
-39 Tilt Wheel
2
-40 Multifunction Lever
2
-46 Exterior Lamps
2
-49 Interior Lamps
2
-51 Mirrors
2
-55 Storage Compartments
2
-61 Ashtrays and Cigarette Lighter
2
-63 Sun Visors
2
-63 Universal Transmitter
2
-67 Cellular Telephone (If Equipped)
2
-67 OnStar
System (If Equipped)
2
-68 Instrument Panel
2
-70 Instrument Panel Cluster
2
-72 Warning Lights, Gages and Indicators

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This device complies with RSS-210 of Industry Canada.
Operation is subject to the following two conditions:
(1) this device may not cause interference, and (2) this
device must accept any interference received, including
interference that may cause undesired operation of
the device.
Changes or modifications to this system by other than an
authorized service facility could void authorization to
use this equipment.
This system has a range of about 3 feet (1 m) up to 30 feet
(9 m). At times you may notice a decrease in range. This
is normal for any remote keyless entry system. If the
transmitter does not work or if you have to stand closer to
your vehicle for the transmitter to work, try this:

Check to determine if battery replacement or
transmitter resynchronization is necessary. See the
instructions that follow.

Check the distance. You may be too far from your
vehicle. You may need to stand closer during rainy
or snowy weather.

Check the location. Other vehicles or objects may be
blocking the signal. Take a few steps to the left or
right, hold the transmitter higher, and try again.
If you're still having trouble, see your dealer or a
qualified technician for service.
Operation
The driver's door will unlock automatically when
UNLOCK is pressed. If UNLOCK is pressed again
within five seconds, the passenger's doors will also
unlock. All doors will lock when LOCK is pressed.
The tailgate or panel doors will unlock when the
REAR 2X button is pressed twice within five seconds,
as long as the ignition is turned to OFF. If the ignition is
on, the REAR 2X button will only work if the
transmission is in PARK (P).
The system will turn on the interior lamps for about
40 seconds (or until the ignition is turned to RUN),
when you unlock the doors, tailgate or panel doors. The
interior lamps will go off when you lock the doors.
Operating the keyless entry transmitter may interact
with the theft
-deterrent system. See ªTheft-Deterrent
Systemº in the Index.

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Automatic Transmission Operation
There are several different positions for your shift lever.
Your vehicle features an electronic shift position
indicator within the instrument cluster. This display
must be powered anytime the shift lever is capable of
being moved out of PARK (P). This means that if your
key is in OFF, rather than LOCK, there will be a small
current drain on your battery which could discharge
your battery over a period of time. If you need to leave
your key in the ignition in OFF for an extended period
for any reason, it is recommended that you disconnect
the battery cable from the battery to prevent discharging
your battery.PARK (P): This locks your rear wheels. It's the best
position to use when you start your engine because your
vehicle can't move easily.
CAUTION:
It is dangerous to get out of your vehicle if the
shift lever is not fully in PARK (P) with the
parking brake firmly set. Your vehicle can roll.
Don't leave your vehicle when the engine is
running unless you have to. If you have left the
engine running, the vehicle can move suddenly.
You or others could be injured. To be sure your
vehicle won't move, even when you're on fairly
level ground, always set your parking brake and
move the shift lever to PARK (P).
See ªShifting Into PARK (P)º in the Index. If
you're pulling a trailer, see ªTowing a Trailerº in
the Index.

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AUTOMATIC OVERDRIVE (
): This position is for
normal driving. If you need more power for passing,
and you're:

Going less than about 35 mph (56 km/h), push your
accelerator pedal about halfway down.

Going about 35 mph (56 km/h) or more, push the
accelerator all the way down.
You'll shift down to the next gear and have
more power.
AUTOMATIC OVERDRIVE (
) can be used when
towing a trailer, carrying a heavy load, driving on steep
hills or for off
-road driving. You may want to shift the
transmission to THIRD (3) or, if necessary, a lower gear
selection if the transmission shifts too often.
THIRD (3): This position is also used for normal
driving, however, it offers more power and lower fuel
economy than AUTOMATIC OVERDRIVE (
).
SECOND (2): This position gives you more power but
lower fuel economy. You can use SECOND (2) on hills.
It can help control your speed as you go down steep
mountain roads, but then you would also want to use
your brakes off and on.If you manually select SECOND (2), the transmission will
drive in second gear. You may use this feature for reducing
torque to the rear wheels when you are trying to start your
vehicle from a stop on slippery road surfaces.
FIRST (1): This position gives you even more power
(but lower fuel economy) than SECOND (2). You can
use it on very steep hills, or in deep snow or mud. If the
selector lever is put in FIRST (1) while the vehicle is
moving forward, the transmission won't shift into first
gear until the vehicle is going slowly enough.NOTICE:
If your rear wheels can't rotate, don't try to
drive. This might happen if you were stuck in
very deep sand or mud or were up against a solid
object. You could damage your transmission.
Also, if you stop when going uphill, don't hold
your vehicle there with only the accelerator
pedal. This could overheat and damage the
transmission. Use your brakes or shift into
PARK (P) to hold your vehicle in position on
a hill.

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The transfer case switches are below and to the left of
the climate controls. Use these switches to shift into and
out of four
-wheel drive. You can choose among four
driving settings:
2HI: This setting is used for driving in most situations.
Your front axle is not engaged in two
-wheel drive. This
setting also provides the best fuel economy.
AUTO 4WD: This setting is ideal for use when road
conditions are variable. When driving your vehicle in
AUTO 4WD, the front axle is engaged, but the vehicle'spower is sent only to the rear wheels. When the vehicle
senses a loss of traction, the system will automatically
engage four
-wheel drive. Driving in this mode results in
lower fuel economy than 2HI.
4HI: Use 4HI when you need extra traction, such as on
snowy or icy roads or in most off
-road situations. This
setting also engages your front axle to help drive
your vehicle.
4LO: This setting also engages your front axle and
delivers extra torque. You may never need 4LO. It sends
maximum power to all four wheels. You might choose
4LO if you are driving off
-road in deep sand, deep mud,
deep snow and climbing or descending steep hills.
CAUTION:
Shifting the transfer case to NEUTRAL can
cause your vehicle to roll even if the transmission
is in PARK (P). You or someone else could be
seriously injured. Be sure to set the parking
brake before placing the transfer case in
NEUTRAL. See ªParking Brakeº in the Index.

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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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If you have to leave your vehicle with the engine
running, be sure your vehicle is in PARK (P) and the
parking brake is firmly set before you leave it. After you
move the shift lever into PARK (P), hold the regular
brake pedal down. Then, see if you can move the shift
lever away from PARK (P) without first pulling it
toward you. If you can, it means that the shift lever
wasn't fully locked into PARK (P).
Torque Lock
If you are parking on a hill and you don't 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 find it difficult to pull the
shift lever out of PARK (P). This is called ªtorque lock.º
To prevent torque lock, set the parking brake and then
shift into PARK (P) properly before you leave the
driver's seat. To find out how, see ªShifting Into
PARK (P)º in the Index.
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, so
you can pull the shift lever out of PARK (P).
Shifting Out of PARK (P)
Your vehicle has a brake-transmission shift interlock
system. You have to fully apply your regular brakes
before you can shift from PARK (P) when the ignition is
in RUN. See ªAutomatic Transmissionº in the Index.
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 gear you want.
If you ever hold the brake pedal down but still can't
shift out of PARK (P), try this:
1. Turn the key to the OFF ignition position.
2. Apply and hold the brake until the end of Step 4.
3. Shift the vehicle to NEUTRAL (N).
4. Start the vehicle and then shift to the drive gear
you want.
5. Have the brake
-transmission shift interlock system
fixed as soon as you can.

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Recreational Vehicle Towing
There may be times when you want to tow your vehicle
behind another vehicle for use at your destination. Be
sure to use the proper towing equipment designed for
recreational vehicle towing. Follow the instructions for
the towing equipment.
Four-Wheel Drive Vehicles
CAUTION:
Shifting the transfer case into NEUTRAL (N) can
cause your vehicle to roll even if the transmission
is in PARK (P), for an automatic transmission.
You or others could be injured. Make sure the
parking brake is firmly set before you shift the
transfer case into NEUTRAL (N).