2003 GMC YUKON Ignition

Ignition Positions
With the key in the ignition switch, you can turn the key
to four different positions.
A (LOCK):This position locks your ignition and
transmission. It’s a theft-deterrent feature. You will only
be able to remove your key when the ignition is
turned to LOCK.
B (ACCESSORY):This position lets you use things like
the radio, power windows and the windshield wipers
when the engine is off.Notice:If your key seems stuck in LOCK and you
can’t turn it, be sure you are using the correct key;
if so, is it all the way in? Turn the key only with
your hand. Using a tool to force it could break the
key or the ignition switch. If none of these works,
then your vehicle needs service.
C (RUN):This is the position for driving.
D (START):This position starts your engine.
Retained Accessory Power (RAP)
Your vehicle may be equipped with a Retained
Accessory Power (RAP) feature which will allow certain
features on your vehicle to continue to work up to
10 minutes after the ignition key is turned to OFF.
Your radio, power windows, sunroof (if equipped), and
OnStar
®System (if equipped) will work when the ignition
key is in RUN or ACCESSORY. Once the key is
turned from RUN to LOCK, these features will continue
to work for up to 10 minutes or until a door is opened.
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Starting Your Engine
Move your shift lever to PARK (P) or NEUTRAL (N).
Your engine won’t start in any other position–that’sa
safety feature. To restart when you’re already moving,
use NEUTRAL (N) only.
Notice:Don’t try to shift to PARK (P) if your
vehicle is moving. If you do, you could damage the
transmission. Shift to PARK (P) only when your
vehicle is stopped.
1. With your foot off the accelerator pedal, turn the
ignition key to START. When the engine starts,
let go of the key. The idle speed will go down as
your engine gets warm.
Notice:Holding your key in START for longer than
15 seconds at a time will cause your battery to
be drained much sooner. And the excessive heat
can damage your starter motor. Wait about
15 seconds between each try to help avoid draining
your battery or damaging your starter.
2. If it doesn’t start within 10 seconds, push the
accelerator pedal all the way to theoor, while you
hold the ignition key in START. When the engine
starts, let go of the key and let up on the accelerator
pedal. Wait about 15 seconds between each try.When starting your engine in very cold weather (below
0°For−18°C), do this:
1. With your foot off the accelerator pedal, turn the
ignition key to START and hold it there up to
15 seconds. When the engine starts, let go of
the key.
2. If your engine still won’t start (or starts but then
stops), it could beooded with too much gasoline.
Try pushing your accelerator pedal all the way to the
oor and holding it there as you hold the key in
START for about three seconds. When the engine
starts, let go of the key and accelerator. If the
vehicle starts briey but then stops again, do the
same thing, but this time keep the pedal down
forve or six seconds. This clears the extra
gasoline from the engine.
Notice:Your engine is designed to work with the
electronics in your vehicle. If you add electrical
parts or accessories, you could change the way the
engine operates. Before adding electrical equipment,
check with your dealer. If you don’t, your engine
might not perform properly.
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g(4LO):This setting also engages your front axle
and delivers extra torque. You may never need
this setting. 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″Parking Brake″in the
Index.
NEUTRAL:Shift the vehicle’s transfer case to
NEUTRAL only when towing your vehicle. See
Recreational Vehicle Towing on page 4-55orTowing
Your Vehicle on page 4-54for more information.Indicator lights in the switches show which setting you
are in. The indicator lights will come on briey 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 willash 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 message stays on, you should
take your vehicle to your dealer for service. See″Service
4WD message″underDriver Information Center (DIC)
on page 3-53.
Shifting into 4HI or AUTO 4WD
Press and release the 4 hi or AUTO 4WD switch. This
can be done at any speed (except when shifting
from 4LO), and the indicator light willash while shifting.
It will remain illuminated when the shift is completed.
Shifting into 2HI
Press and release the 2 hi switch. This can be done at
any speed (except when shifting from 4LO).
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Shifting into 4LO
To shift to the 4 lo position, the ignition must be in RUN
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 4 lo switch. You must wait for the
4LO indicator light to stopashing and remain
illuminated before shifting your transmission in gear.
Notice:Shifting the transmission into gear before
the 4LO indicator light has stoppedflashing
could damage the transfer case. To help avoid
damaging your vehicle, always wait for the
4LO indicator light to stopflashing before shifting
your transmission into gear.
It is typical for your vehicle to exhibit signicant
engagment noise and bump when shifting between
4LO and 4HI ranges or from NEUTRAL with the engine
running.
If the 4 lo switch is pressed when your vehicle is in gear
and/or moving, the 4LO indicator light willash 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 ignition in RUN. 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 stopashing
and remain illuminated before shifting your transmission
into gear.
Notice:Shifting the transmission into gear before
the 4LO indicator light has stoppedflashing
could damage the transfer case. To help avoid
damaging your vehicle, always wait for the
4LO indicator light to stopflashing before shifting
your transmission into gear.
It is typical for your vehicle to exhibit signicant
engagment noise and bump when shifting between
4LO and 4HI ranges or from NEUTRAL with the engine
running.
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 willash 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).
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Shifting into NEUTRAL
To shift the transfer case to NEUTRAL do the following:
1. Make sure the vehicle is parked so that it will
not roll.
2. Set the parking brake.
3. Start the vehicle or turn the ignition to RUN.
4. Connect the vehicle to the towing vehicle.
5. Put the transmission in NEUTRAL (N).
6. Shift the transfer case to 2HI.
7. 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.
8. Shift the transmission to REVERSE (R) for one
second, then shift the transmission to DRIVE (D)
for one second.
9. Turn the ignition off.
10. Place the transmission shift lever in PARK (P).
11. 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. Shift the transmission to NEUTRAL (N) and turn the
ignition to RUN with the engine off.
3. Press the button for the desired transfer case shift
position (2HI, 4HI, AUTO 4WD OR 4 LO).
4. After the transfer case has shifted out of NEUTRAL
the red light will go out.
5. You may start the engine and shift the transmission
to the desired position.
Excessively shifting the transfer case into or out of the
different modes may cause the transfer case to
enter the shift protection mode. This will protect the
transfer case from possible damage and will
only allow the transfer case to respond to one shift
per 10 seconds. The transfer case may stay in
this mode for up to three minutes.
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NEUTRAL:Shift the vehicle’s transfer case to
NEUTRAL only when towing your vehicle. See
Recreational Vehicle Towing on page 4-55orTowing
Your Vehicle on page 4-54for more information.
Indicator lights in the switches show which setting you
are in. The indicator lights will come on briey 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 willash 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 message stays on, you should
take your vehicle to your dealer for service. See
SERVICE 4WD underDriver Information Center (DIC)
on page 3-53.
Shifting into 4LO
To shift to the 4LO position, the ignition must be in RUN
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 stopashing and remain
illuminated before shifting your transmission in gear.Notice:Shifting the transmission into gear before
the 4LO indicator light has stoppedflashing could
damage the transfer case. To help avoid damaging
your vehicle, always wait for the 4LO indicator light
to stopflashing 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 willash 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.
When in 4LO, the vehicle stability is disabled. For more
information seeStabilitrak
®System on page 4-12.
Shifting Out of 4LO
To shift from 4LO to AWD your vehicle must be stopped
or moving less than 3 mph (4.8 km/h) with the
transmission in NEUTRAL (N) and the ignition in RUN.
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 AWD switch. You must wait for the AWD
indicator light to stopashing and remain illuminated
before shifting your transmission into gear.
If the AWD switch is pressed when your vehicle is in
gear and/or moving, the AWD indicator light willash 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).
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Shifting into NEUTRAL
To shift the transfer case to NEUTRAL do the following:
1. Make sure the vehicle is parked so that it will
not roll
2. Set the parking brake.
3. Start the vehicle or turn the ignition to RUN.
4. Connect the vehicle to the towing vehicle.
5. Put the transmission in NEUTRAL (N).
6. Shift the transfer case to AWD.
7. Simultaneously press and hold the Stabilitrak
®and
4LO buttons for 10 seconds. The red NEUTRAL
light will come on when the transfer case shift
to NEUTRAL is complete.8. Shift the transmission to REVERSE (R) for one
second, then shift the transmission to DRIVE (D)
for one second.
9. Turn the ignition to LOCK.
10. Place the transmission shift lever in PARK (P).
11. 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. Shift the transmission to NEUTRAL (N) and turn the
ignition to RUN with the engine off.
3. Press the button for the desired transfer case shift
position (All-Wheel Drive or 4LO).
4. After the transfer case has shifted out of NEUTRAL
the red light will go out.
5. You may start the engine and shift the transmission
to the desired position.
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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.
A chime will activate and the warning light willash
when the parking brake is applied and the vehicle
is moving at least 3 mph (5 km/h) for at least
three seconds.To release the parking brake, hold the regular brake
pedal down. Pull the bottom edge of the lever, located
above the parking brake pedal, with the parking
brake symbol, 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,
seeTowing a Trailer on page 4-61.
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