2008 CHEVROLET SILVERADO light

If the engine still does not start, and the key appears to
be undamaged, try another ignition key. At this time, you
may also want to check the fuse, seeFuses and Circuit
Breakers on page 5-125. If the engine still does not start
with the other key, your vehicle needs service. If your
vehicle does start, the rst key may be faulty. See your
dealer/retailer who can service the PASS-Key
®III+ to
have a new key made. In an emergency, contact
Roadside Assistance.
It is possible for the PASS-Key
®III+ decoder to learn
the transponder value of a new or replacement key.
Up to 10 keys may be programmed for the vehicle.
The following procedure is for programming additional
keys only. If all the currently programmed keys are
lost or do not operate, you must see your dealer/retailer
or a locksmith who can service PASS-Key
®III+ to
have keys made and programmed to the system.
See your dealer/retailer or a locksmith who can service
PASS-Key
®III+ to get a new key blank that is cut
exactly as the ignition key that operates the system.To program the new additional key:
1. Verify that the new key has a
1stamped on it.
2. Insert the original, already programmed, key in the
ignition and start the engine. If the engine will not
start, see your dealer/retailer for service.
3. After the engine has started, turn the key to
LOCK/OFF, and remove the key.
4. Insert the new key to be programmed and turn it to
the ON/RUN position within ve seconds of turning
the ignition to the LOCK/OFF position in Step 3.
The security light will turn off once the key has been
programmed.
5. Repeat Steps 1 through 4 if additional keys are to
be programmed.
If you lose or damage your PASS-Key
®III+ key, see
your dealer/retailer or a locksmith who can service
PASS-Key
®III+ to have a new key made.
Do not leave the key or device that disarms or
deactivates the theft deterrent system in the vehicle.
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Tow/Haul ModeIf your vehicle has an automatic transmission, it
has a tow/haul mode. If your vehicle has an Allison
or Hydra-Matic
®6-speed automatic transmission see
“Tow/Haul Mode (Allison or Hydra-Matic®6-Speed
Automatic Transmission®) following. The tow/haul
mode adjusts the transmission shift pattern to reduce
shift cycling, providing increased performance, vehicle
control, and transmission cooling when towing or hauling
heavy loads.
The selector button is located on the end of the shift
lever. Turn the tow/haul on and off by pressing the
button. When the tow/haul is on, a light on the
instrument panel cluster will come on.
SeeTow/Haul Mode Light on page 3-54for more
information.
Also see Tow Haul Mode underTowing a Trailer on
page 4-55for more information.
2-34

Tow/Haul Mode (Allison Transmission®
or Hydra-Matic®6-Speed Automatic
Transmission)
If your vehicle has an Allison or Hydra-Matic®6-speed
automatic transmission®, it has a tow/haul mode.
The tow/haul mode adjusts the transmission shift pattern
to reduce shift cycling, providing increased performance,
vehicle control, and transmission cooling when towing
or hauling heavy loads.
Turn the tow/haul mode on and off by pressing the
button, located on the end of the shift lever. When the
tow/haul is on, a light on the instrument panel cluster will
come on.
SeeTow/Haul Mode Light on page 3-54for more
information.
Also see “Tow Haul Mode” underTowing a Trailer on
page 4-55for more information.
2-35

Manual Transfer Case
The transfer case shift lever is on the oor to the right
of the driver. Use this lever to shift into and out of
Four-Wheel Drive.A Four-Wheel Drive
indicator light comes
on when you shift into
four-wheel drive and the
front axle engages. See
Four-Wheel-Drive Light
on page 3-54.
Some delay between shifting and when the indicator
light comes on is normal.
Recommended Transfer Case Settings
Driving ConditionsTransfer Case Settings
2m4m4nN
Normal YES
Severe YES
Extreme YES
Vehicle in Tow* YES
*SeeRecreational Vehicle Towing on page 4-50
Towing Your Vehicle on page 4-50
Notice:Driving on clean, dry pavement in
four-wheel drive for an extended period of time can
cause premature wear on your vehicle’s powertrain.
Do not drive on clean, dry pavement in Four-Wheel
Drive for extended periods of time.
2-37

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 NEUTRAL (N).
{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. SeeParking Brake on
page 2-50.
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 will
end up in NEUTRAL. This is normal, and is a function
of the gear teeth aligning in your transfer case. When
this happens, make sure the engine is on, shift your
transmission momentarily to drive and back to
NEUTRAL, and then complete the 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.
2-40

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 NEUTRAL (N).
Shift the transfer case in one continuous motion into or
out of the NEUTRAL position.
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 ConditionsTransfer Case Settings
2m4m4nN
Normal YES
Severe YES
Extreme YES
Vehicle in Tow* YES
*SeeRecreational Vehicle Towing on page 4-50
Towing Your Vehicle on page 4-50
You can choose among four driving settings:
Indicator lights in the dial 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 ashes 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.
2-41

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 RUN and the vehicle must be stopped
or moving less than 3 mph (5 km/h) with the transmission
in NEUTRAL (N). The preferred method for shifting into
Four-Wheel-Drive Low is to have your 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 ashing and
remain on before shifting your transmission in gear.Notice:Shifting the transmission into gear before
the requested mode indicator light has stopped
ashing could damage the transfer case. To help
avoid damaging your vehicle, always wait for the
mode indicator lights to stop ashing before shifting
the transmission into gear.
It is typical for your vehicle to exhibit signicant
engagement noise and bump when shifting between
Four-Wheel-Drive Low and Four-Wheel-Drive High
ranges or from NEUTRAL with the engine running.
If the knob is turned to the Four-Wheel-Drive Low
position when your vehicle is in gear and/or moving,
the Four-Wheel-Drive Low indicator light will ash for
30 seconds and not complete the shift unless your
vehicle is moving less than 3 mph (5 km/h) and the
transmission is in NEUTRAL (N). After 30 seconds the
transfer case will shift to Four-Wheel-Drive High mode.
2-43

Shifting Out of Four-Wheel-Drive Low
To shift from Four-Wheel-Drive Low to
Four-Wheel-Drive High, or Two-Wheel-Drive High,
your vehicle must be stopped or moving less than 3 mph
(5 km/h) with the transmission in NEUTRAL (N) and the
ignition in ON/RUN. The preferred method for shifting
out of Four-Wheel-Drive Low is to have your 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 ashing
and remain on before shifting the transmission into gear.
Notice:Shifting the transmission into gear before
the requested mode indicator light has stopped
ashing could damage the transfer case. To help
avoid damaging your vehicle, always wait for the
mode indicator lights to stop ashing before shifting
the transmission into gear.
It is typical for your vehicle to exhibit signicant
engagement noise and bump when shifting between
Four-Wheel-Drive Low and Four-Wheel-Drive High
ranges or from NEUTRAL with the engine running.
If the knob is turned to the Four-Wheel-Drive High, or
Two-Wheel-Drive High switch position when your vehicle
is in gear and/or moving, the Four-Wheel-Drive High,
or Two-Wheel-Drive High indicator light will ash 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 NEUTRAL (N).
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 and press and hold the
regular brake pedal. SeeParking Brake on
page 2-50for more information.
3. Start the vehicle or turn the ignition to ON/RUN.
4. Shift the transmission to NEUTRAL (N).
5. Shift the transfer case to Two-Wheel-Drive High.
6. Turn the transfer case dial clockwise to NEUTRAL
till it stops and hold it for 10 seconds. Then slowly
release the dial to the four low position. The
NEUTRAL light will come on when the transfer
case shift to NEUTRAL is complete.
7. If the engine is running, verify that the transfer case
is in NEUTRAL (N) by shifting the transmission to
REVERSE (R) for one second, then shift the
transmission to DRIVE (D) for one second.
8. Turn the ignition to ACC/ACCESSORY, which will
turn the engine off.
9. Place the transmission shift lever in PARK (P).
10. Release the parking brake prior to moving
the vehicle.
11. Turn the ignition to LOCK/OFF.
2-44