light GMC SIERRA 2010 Service Manual

Shifting In or Out of Four-Wheel-Drive Low
Notice:Shifting the transfer case into
Four-Wheel-Drive Low while moving at speeds
faster than 3 mph (5 km/h) may cause premature
wear to the transfer case, and may cause the gears
to grind. To avoid causing premature wear, and
grinding the gears, do not shift the transfer case
into Four-Wheel-Drive Low while the vehicle is
moving faster than 3 mph (5 km/h).
Shifting into Four-Wheel-Drive Low should be done,
if possible, with the vehicle at a slight roll, 3 mph
(5 km/h) or less.
.Shift the transmission into N (Neutral).
{WARNING:
Shifting the transfer case to Neutral can cause
the vehicle to roll even if the transmission is in
P (Park). 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 on page 3‑50.
.Shifting into Four-Wheel-Drive Low with the vehicle
at a stop may be more difficult. You may be unable
to complete the shift to Four-Wheel-Drive Low, and
the transfer case will end up in N (Neutral). This is
normal, and is a function of the gear teeth aligning
in the transfer case. When this happens, make
sure the engine is on, shift the transmission
momentarily to D (Drive) and back to N (Neutral),
and then complete the transfer case shift.
.Shift the transfer case shift lever in one continuous
motion into the Four-Wheel-Drive Low position.
.When Four-Wheel-Drive Low do not drive faster
than 45 mph. This will reduce wear and extend the
life of your transfer case.
Shifting In or Out of Neutral
1. With the vehicle running and the engine at an idle set the parking brake.
2. Place the transmission into N (Neutral).
Shift the transfer case in one continuous motion into or
out of the N (Neutral) position.
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Electronic Transfer Case
The transfer case knob
is located next to the
steering column.
Use the dial to shift into and out of four-wheel drive.
Recommended Transfer Case Settings
Driving Conditions Transfer Case Settings
2m 4m4n N
Normal YES
Severe YES
Extreme YES
Vehicle in Tow* YES
*See Recreational Vehicle Towing
on page 5‑43or
Towing Your Vehicle on page 5‑43
You can choose among four driving settings:
Indicator lights in the dial 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 the vehicle to your
dealer/retailer for service. An indicator light flashes
while shifting the transfer case and remains 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.
2
m(Two-Wheel-Drive High): This setting is used for
driving in most street and highway situations. The front
axle is not engaged in Two-Wheel Drive. This setting
also provides the best fuel economy.
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Shifting Into Two-Wheel-Drive High
Turn the knob to the Two-Wheel-Drive High position.
This can be done at any speed, except when shifting
from Four-Wheel-Drive Low. See Shifting Out of
Four-Wheel-Drive Low for more information.
Shifting Into Four-Wheel Drive Low
When Four-Wheel-Drive Low is engaged, vehicle speed
should be kept below 45 mph. Extended high-speed
operation in Four-Wheel-Drive Low may damage or
shorten the life of the drivetrain.
To shift to the Four-Wheel-Drive Low position, the
ignition must be in ON/RUN and the vehicle must be
stopped or moving less than 3 mph (5 km/h) with the
transmission in N (Neutral). The preferred method for
shifting into Four-Wheel-Drive Low is to have the
vehicle moving 1 to 2 mph (1.6 to 3.2 km/h). Turn the
knob to the Four-Wheel-Drive Low position. You must
wait for the Four-Wheel-Drive Low indicator light to stop
flashing and remain on before shifting the transmission
in gear.Notice:
Shifting the transmission into gear before
the requested mode indicator light has stopped
flashing could damage the transfer case. To help
avoid damaging the vehicle, always wait for the
mode indicator lights to stop flashing before
shifting the transmission into gear.
It is typical for the vehicle to exhibit significant
engagement noise and bump when shifting between
Four-Wheel-Drive Low and Four-Wheel-Drive High
ranges or from transfer case N (Neutral) with the engine
running.
If the knob is turned to the Four-Wheel-Drive Low
position when the vehicle is in gear and/or moving,
the Four-Wheel-Drive Low indicator light will flash for
30 seconds and not complete the shift unless the
vehicle is moving less than 3 mph (5 km/h) and the
transmission is in N (Neutral). After 30 seconds the
transfer case will shift to Four-Wheel-Drive High mode.
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Shifting Out of Four-Wheel-Drive Low
To shift from Four-Wheel-Drive Low to
Four-Wheel-Drive High, or Two-Wheel-Drive High, the
vehicle must be stopped or moving less than 3 mph
(5 km/h) with the transmission in N (Neutral) and the
ignition in ON/RUN. The preferred method for shifting
out of Four-Wheel-Drive Low is to have the vehicle
moving 1 to 2 mph (1.6 to 3.2 km/h). Turn the knob to the
Four-Wheel-Drive High, or Two-Wheel-Drive High
position. You must wait for the Four-Wheel-Drive High,
or Two-Wheel-Drive High indicator light to stop flashing
and remain on before shifting the transmission
into gear.
Notice:Shifting the transmission into gear before
the requested mode indicator light has stopped
flashing could damage the transfer case. To help
avoid damaging the vehicle, always wait for the
mode indicator lights to stop flashing before
shifting the transmission into gear.
It is typical for the vehicle to exhibit significant
engagement noise and bump when shifting between
Four-Wheel-Drive Low and Four-Wheel-Drive High
ranges or from transfer case N (Neutral) with the engine
running. If the knob is turned to the Four-Wheel-Drive High,
or Two-Wheel-Drive High switch position when the
vehicle is in gear and/or moving, the Four-Wheel-Drive
High, or Two-Wheel-Drive High indicator light will flash
for 30 seconds but will not complete the shift unless
your vehicle is moving less than 3 mph (5 km/h) and the
transmission is in N (Neutral).
Shifting into Neutral
To shift the transfer case to N (Neutral) do the following:
1. Make sure the vehicle is parked so that it will not roll.
2. Set the parking brake and press and hold the regular brake pedal. See Parking Brake
on
page 3‑50for more information.
3. Start the vehicle or turn the ignition to ON/RUN.
4. Shift the transmission to N (Neutral).
5. Shift the transfer case to Two-Wheel-Drive High.
6. Turn the transfer case dial clockwise to N (Neutral) until it stops and hold it there until the Neutral light
starts blinking. This will take at least 10 seconds.
Then slowly release the dial to the four low
position. The N (Neutral) light will come on when
the transfer case shift to N (Neutral) is complete.
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7. If the engine is running, verify that the transfercase is in N (Neutral) by shifting the transmission
to R (Reverse) for one second, then shift the
transmission to D (Drive) for one second.
8. Turn the ignition to ACC/ACCESSORY, which will turn the engine off.
9. Place the transmission shift lever in P (Park).
10. Release the parking brake prior to moving the vehicle.
11. Turn the ignition to LOCK/OFF.
Shifting Out of Neutral
To shift the transfer case out of N (Neutral) do the
following: 1. Set the parking brake and apply the regular brake pedal.
2. Turn the ignition to ON/RUN with the engine off, and shift the transmission to N (Neutral). 3. Turn the transfer case dial to
Two-Wheel-Drive High.
After the transfer case has shifted out of
N (Neutral), the N (Neutral) light will go out.
4. Release the parking brake prior to moving the vehicle.
Notice: Shifting the transmission into gear before
the requested mode indicator light has stopped
flashing could damage the transfer case. To help
avoid damaging the vehicle, always wait for the
mode indicator lights to stop flashing before
shifting the transmission into gear.
5. 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.
3-45

Automatic Transfer Case
The transfer case knob
is located next to the
steering column.
Use the dial to shift into and out of Four-Wheel Drive.
You can choose among five driving settings:
Indicator lights in the dial 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 the vehicle to your dealer/
retailer 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. 2
m(Two-Wheel-Drive High):
This setting is used for
driving in most street and highway situations. The front
axle is not engaged in Two-Wheel Drive. This setting
also provides the best fuel economy.
AUTO (Automatic Four-Wheel Drive) : This setting is
ideal for use when road surface traction conditions are
variable. When driving the vehicle in AUTO, the front
axle is engaged, but the vehicle's power is sent only to
the front and rear wheels automatically based on driving
conditions. Driving in this mode results in slightly lower
fuel economy than Two-Wheel-Drive High.
4
m(Four-Wheel-Drive High): Use the
Four-Wheel-Drive High position when extra traction is
needed, such as on snowy or icy roads or in most
off-road situations. This setting also engages the front
axle to help drive the vehicle. This is the best setting to
use when plowing snow.
4
n(Four-Wheel-Drive Low): This setting also engages
the front axle and delivers extra torque. You may never
need this setting. It sends maximum power to all four
wheels. You might choose Four-Wheel-Drive Low if you
are driving off-road in deep sand, deep mud, deep
snow, and while climbing or descending steep hills.
3-46

If the vehicle has StabiliTrak®, shifting into
Four-Wheel-Drive Low will turn Traction Control and
StabiliTrak
®off. See StabiliTrak®System on page 5‑6.
{WARNING:
Shifting the transfer case to N (Neutral) can cause
the vehicle to roll even if the transmission is in
P (Park). You or someone else could be seriously
injured. Be sure to set the parking brake before
placing the transfer case in N (Neutral). See
Parking Brake on page 3‑50.
N (Neutral) : Shift the vehicle's transfer case to
N (Neutral) only when towing the vehicle. See
Recreational Vehicle Towing
on page 5‑43or Towing
Your Vehicleon page 5‑43for more information.
If the SERVICE 4–Wheel Drive message stays on,
you should take the vehicle to your dealer/retailer for
service. See “Service 4–Wheel Drive message” under
DIC Warnings and Messages on page 4‑65.
Shifting Into Four-Wheel-Drive High or
AUTO (Automatic Four-Wheel Drive)
Turn the knob to the Four-Wheel-Drive High or AUTO
position. This can be done at any speed, except when
shifting from Four-Wheel-Drive Low. The indicator light
will flash while shifting. It will remain on when the shift is
completed.
Shifting Into Two-Wheel-Drive High
Turn the knob to the Two-Wheel-Drive High position.
This can be done at any speed, except when shifting
from Four-Wheel-Drive Low. The indicator light will
flash while shifting. It will remain on when the shift is
completed.
Shifting Into Four-Wheel-Drive Low
When Four-Wheel-Drive Low is engaged, vehicle speed
should be kept below 45 mph. Extended high-speed
operation in Four-Wheel-Drive Low may damage or
shorten the life of the drivetrain.
To shift to the Four-Wheel-Drive Low position, the
ignition must be in ON/RUN and the vehicle must be
stopped or moving less than 3 mph (5 km/h) with the
transmission in N (Neutral). The preferred method for
shifting into Four-Wheel-Drive Low is to have the
vehicle moving 1 to 2 mph (1.6 to 3.2 km/h). Turn the
knob to the Four-Wheel-Drive Low position.
3-47

You must wait for the Four-Wheel-Drive Low indicator
light to stop flashing and remain on before shifting the
transmission into gear.
Notice:Shifting the transmission into gear before
the requested mode indicator light has stopped
flashing could damage the transfer case. To help
avoid damaging the vehicle, always wait for the
mode indicator lights to stop flashing before
shifting the transmission into gear.
It is typical for the vehicle to exhibit significant
engagement noise and bump when shifting between
Four-Wheel-Drive Low and Four-Wheel-Drive High
ranges or from N (Neutral) with the engine running.
If the knob is turned to the Four-Wheel-Drive Low
position when the vehicle is in gear and/or moving,
the Four-Wheel-Drive Low indicator light will flash for
30 seconds and not complete the shift unless the
vehicle is moving less than 3 mph (5 km/h) and the
transmission is in N (Neutral). After 30 seconds the
transfer case will shift to Four-Wheel-Drive High mode.
Shifting Out of Four-Wheel-Drive Low
To shift from Four-Wheel-Drive Low to
Four-Wheel-Drive High, AUTO or Two-Wheel-Drive
High, the vehicle must be stopped or moving less than
3 mph (5 km/h) with the transmission in N (Neutral) and
the ignition in ON/RUN. The preferred method for shifting out of Four-Wheel-Drive Low is to have the
vehicle moving 1 to 2 mph (1.6 to 3.2 km/h). Turn the
knob to the Four-Wheel-Drive High, AUTO or
Two-Wheel-Drive High position. You must wait for the
Four-Wheel-Drive High, AUTO or Two-Wheel-Drive
High indicator light to stop flashing and remain on
before shifting the transmission into gear.
Notice:
Shifting the transmission into gear before
the requested mode indicator light has stopped
flashing could damage the transfer case. To help
avoid damaging the vehicle, always wait for the
mode indicator lights to stop flashing before
shifting the transmission into gear.
It is typical for the vehicle to exhibit significant
engagement noise and bump when shifting between
Four-Wheel-Drive Low and Four-Wheel-Drive High
ranges or from N (Neutral) with the engine running.
If the knob is turned to the Four-Wheel-Drive High,
AUTO, or Two-Wheel-Drive High switch position
when the vehicle is in gear and/or moving, the
Four-Wheel-Drive High, AUTO or Two-Wheel-Drive
High indicator light will flash for 30 seconds but will not
complete the shift unless the vehicle is moving less
than 3 mph (5 km/h) and the transmission is in
N (Neutral).
3-48

Shifting into Neutral
To shift the transfer case to N (Neutral) do the following:1. Make sure the vehicle is parked so that it will not roll.
2. Set the parking brake and apply the regular brake pedal. See Parking Brake
on page 3‑50for more
information.
3. Shifting the transfer case into N (Neutral) can be done with or without the engine running. Shifting
without the engine running should be done with the
ignition in ON/RUN.
4. Put the transmission in N (Neutral).
5. Shift the transfer case to Two-Wheel Drive High.
6. Turn the transfer case dial clockwise to N (Neutral) until it stops and hold it there until the N (Neutral)
light starts blinking. This will take at least
10 seconds. Then slowly release the dial to the
four low position. The N (Neutral) light will come on
when the transfer case shift to N (Neutral) is
complete.
7. If the engine is running, make sure that the transfer case is in N (Neutral) by shifting the transmission
to R (Reverse) for one second, then shift the
transmission to D (Drive) for one second.
8. Turn the ignition to ACC/ACCESSORY, which will turn the engine off. 9. Place the transmission shift lever in P (Park).
10. Release the parking brake prior to moving the vehicle.
11. Turn the ignition to LOCK/OFF.Shifting Out of Neutral
To shift out of N (Neutral) do the following: 1. Set the parking brake and apply the regular brake pedal.
2. Turn the ignition to ON/RUN with the engine off, and shift the transmission to N (Neutral).
3. Turn the transfer case dial to Two-Wheel-Drive High, Four-Wheel-Drive High, AUTO.
After the transfer case has shifted out of
N (Neutral), the N (Neutral) light will go out.
4. Release the parking brake prior to moving the vehicle.
Notice: Shifting the transmission into gear before
the requested mode indicator light has stopped
flashing could damage the transfer case. To help
avoid damaging the vehicle, always wait for the
mode indicator lights to stop flashing before
shifting the transmission into gear.
5. Start the engine and shift the transmission to the desired position.
3-49

Parking Brake
Set the parking brake by holding the regular brake
pedal down, then pushing down the parking brake
pedal.If the ignition is on, the brake system warning light will
come on. See
Brake System Warning Light
on
page 4‑39.
Notice: Driving with the parking brake on can
overheat the brake system and cause premature
wear or damage to brake system parts. Make sure
that the parking brake is fully released and the
brake warning light is off before driving.
To release the parking brake, hold the regular brake
pedal down, then push down momentarily on the
parking brake pedal until you feel the pedal release.
Slowly pull your foot up off the park brake pedal. If the
parking brake is not released when you begin to drive,
the brake system warning light will flash and a chime
will sound warning you that the parking brake is still on.
If you are towing a trailer and are parking on a hill, see
Towing a Trailer on page 5‑50.
3-50