engine CHEVROLET TAHOE 2008 3.G User Guide

Adjustable Throttle and Brake Pedal
On vehicles with this feature, you can change the
position of the throttle and brake pedals.
This feature is designed for shorter drivers, since the
pedals cannot move farther away from the standard
position, but can move toward the driver for better
pedal reach.
No adjustment to the pedals can be made when
the vehicle is in REVERSE (R) or while using the
cruise control.
The switch used to adjust
the pedals is located
on the instrument panel
below the climate control
system.
Press the arrow at the bottom of the switch to move the
pedals closer to your body. Press the arrow at the top of
the switch to move the pedals away from your body.Before you start driving, fully press the brake pedal to
conrm the adjustment is right for you. While driving,
make only small adjustments.
Your vehicle may have a memory function which lets
pedal settings be saved and recalled. SeeMemory Seat,
Mirrors, and Pedals on page 1-6for more information.
Engine Coolant Heater
The engine coolant heater, if available, can help in
cold weather conditions at or below 0°F (−18°C)
for easier starting and better fuel economy during
engine warm-up. Plug in the coolant heater at least
four hours before starting your vehicle. An internal
thermostat in the plug-end of the cord may exist
which will prevent engine coolant heater operation
at temperatures above 0°F (−18°C).
To Use the Engine Coolant Heater
1. Turn off the engine.
2. Open the hood and unwrap the electrical cord.
The cord is located on the driver’s side of the
engine compartment, near the power steering
uid reservoir.
3. Plug the cord into a normal, grounded 110-volt
AC outlet.
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{CAUTION:
Plugging the cord into an ungrounded outlet
could cause an electrical shock. Also, the
wrong kind of extension cord could overheat
and cause a re. You could be seriously
injured. Plug the cord into a properly grounded
three-prong 110-volt AC outlet. If the cord will
not reach, use a heavy-duty three-prong
extension cord rated for at least 15 amps.
4. Before starting the engine, be sure to unplug and
store the cord as it was before to keep it away
from moving engine parts. If you do not, it could be
damaged.
How long should you keep the coolant heater plugged
in? The answer depends on the outside temperature, the
kind of oil you have, and some other things. Instead
of trying to list everything here, we ask that you contact
your dealer/retailer in the area where you will be
parking your vehicle. The dealer/retailer can give you
the best advice for that particular area.
Active Fuel Management™
Your vehicle’s V8 engine may have Active Fuel
Management™. This system allows the engine to
operate on either all or half of its cylinders, depending
on the driving conditions.
When less power is required, such as cruising at a
constant vehicle speed, the system will operate in the
half cylinder mode, allowing your vehicle to achieve
better fuel economy. When greater power demands are
required, such as accelerating from a stop, passing,
or merging onto a freeway, the system will maintain
full-cylinder operation.
If your vehicle has an Active Fuel Management™
indicator, seeDIC Operation and Displays (With DIC
Buttons) on page 3-51orDIC Operation and Displays
(Without DIC Buttons) on page 3-56for more information
on using this display.
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Automatic Transmission Operation
If your vehicle is a Two-mode Hybrid, see the Two-mode
Hybrid manual for more information.
If your vehicle is has an automatic transmission,
it has an electronic shift position indicator within the
instrument panel cluster. This display comes on when
the ignition key is turned to the ON/RUN position.
There are several different positions for the shift lever.
See “Range Selection Mode” later in this section.
PARK (P):This position locks your rear wheels. It is
the best position to use when you start the engine
because your vehicle cannot move easily. When parked
on a hill, especially when the vehicle has a heavy
load, you might notice an increase in the effort to shift
out of Park. See Torque Lock (Automatic Transmission)
underShifting Into Park on page 2-43for more
information.
Hydra-Matic
®4-Speed
Automatic Transmission
Allison Transmission®or Hydra-Matic®6-Speed
Automatic Transmission
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{CAUTION:
It is dangerous to get out of the vehicle if the
shift lever is not fully in P (Park) with the
parking brake rmly set. The vehicle can roll.
Do not leave the 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 the vehicle will not move, even
when you are on fairly level ground, always set
the parking brake and move the shift lever to
P (Park). SeeShifting Into Park on page 2-43.
If you are pulling a trailer, seeTowing a Trailer
on page 4-49.
{CAUTION:
If you have Four-Wheel Drive, your vehicle
will be free to roll — even if your shift lever
is in PARK (P) — if your transfer case is in
NEUTRAL. So, be sure the transfer case is
in a drive gear, Two-Wheel Drive High or
Four-Wheel Drive High or Four-Wheel Drive
Low — not in NEUTRAL. SeeShifting Into
Park on page 2-43.
REVERSE (R):Use this gear to back up.
Notice:Shifting to R (Reverse) while the vehicle is
moving forward could damage the transmission.
The repairs would not be covered by the vehicle
warranty. Shift to R (Reverse) only after the vehicle
is stopped.
To rock your vehicle back and forth to get out of snow,
ice, or sand without damaging your transmission,
seeIf Your Vehicle is Stuck in Sand, Mud, Ice,
or Snow on page 4-33.
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NEUTRAL (N):In this position, your engine does not
connect with the wheels. To restart when you are
already moving, use NEUTRAL (N) only. Also, use
NEUTRAL (N) when your vehicle is being towed.
{CAUTION:
Shifting into a drive gear while the engine is
running at high speed is dangerous. Unless
your foot is rmly on the brake pedal, the
vehicle could move very rapidly. You could
lose control and hit people or objects. Do not
shift into a drive gear while the engine is
running at high speed.
Notice:Shifting out of P (Park) or N (Neutral) with
the engine running at high speed may damage
the transmission. The repairs would not be covered
by the vehicle warranty. Be sure the engine is
not running at high speed when shifting the vehicle.DRIVE (D):This position is for normal driving.
It provides the best fuel economy for your vehicle.
If you need more power for passing, and you are:
Going less than about 35 mph (55 km/h), push your
accelerator pedal about halfway down.
Going about 35 mph (55 km/h) or more, push the
accelerator all the way down.
By doing this, the vehicle shifts down to the next
gear and has more power.
DRIVE (D) can be used when towing a trailer, carrying
a heavy load, driving on steep hills, or for off-road
driving. You might want to shift the transmission to a
lower gear selection if the transmission shifts too often.
Downshifting the transmission in slippery road
conditions could result in skidding. See Skidding under
Loss of Control on page 4-11
Your vehicle has a shift stabilization feature that
adjusts the transmission shifting to the current driving
conditions in order to reduce rapid upshifts and
downshifts. This shift stabilization feature is designed to
determine, before making an upshift, if the engine is
able to maintain vehicle speed by analyzing things such
as vehicle speed, throttle position, and vehicle load.
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If the shift stabilization feature determines that a current
vehicle speed cannot be maintained, the transmission
does not upshift and instead holds the current gear.
In some cases, this could appear to be a delayed shift,
however the transmission is operating normally.
Your vehicle’s transmission uses adaptive shift controls.
Adaptive shift controls continually compares key shift
parameters to pre-programmed ideal shifts stored in the
transmissions computer. The transmission constantly
makes adjustments to improve vehicle performance
according to how the vehicle is being used, such as
with a heavy load or when temperature changes.
During this adaptive shift control process, shifting
might feel different as the transmission determines
the best settings.
When temperatures are very cold, the Allison
Transmission
®and Hydra-Matic®6-Speed
transmission’s gear shifting could be delayed providing
more stable shifts until the engine warms up. Shifts
could be more noticeable with a cold transmission.
This difference in shifting is normal.MANUAL MODE (M):This position, is available on
vehicles with the Allison Transmission
®or Hydra-Matic®
6-Speed transmission. It lets drivers select the range
of gears appropriate for current driving conditions. If your
vehicle has this feature, see Range Select Mode
(Allison Transmission
®or Hydra-Matic®6-Speed
transmission) later in this section.
THIRD (3):This position is also used for normal driving.
It reduces vehicle speed more than DRIVE (D) without
using the brakes. You might choose THIRD (3)
instead of DRIVE (D) when driving on hilly, winding
roads, when towing a trailer, so there is less shifting
between gears and when going down a steep hill.
SECOND (2):This position reduces vehicle speed even
more than THIRD (3) without using your brakes. 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 the brakes off and on.
If you manually select SECOND (2) in an automatic
transmission, the transmission will start in second gear.
You can use this feature for reducing the speed of the
rear wheels when you are trying to start your vehicle from
a stop on slippery road surfaces.
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Tow/Haul Mode
Your vehicle has a Tow/Haul mode. The selector button
is located on the end of the column shift lever. You
can use this feature to assist when towing or hauling a
heavy load or if there is a need to charge a battery
installed in a trailer. SeeTowing a Trailer on page 4-49
for more information.When Tow/Haul mode is
selected the Tow/Haul
indicator light will come on.
The Tow/Haul mode works with the Autoride
®feature,
if the vehicle has this, to enhance the ride when
trailering or with a loaded vehicle. SeeAutoride
®
on page 4-49.
Four-Wheel Drive
If your vehicle has four-wheel drive, you can send your
engine’s driving power to all four wheels for extra
traction. Read the part that follows before using
four-wheel drive.
Notice:Driving on clean, dry pavement in
Four-Wheel-Drive High or Four-Wheel-Drive Low for
an extended period of time may cause premature
wear on your vehicle’s powertrain. Do not drive on
clean, dry pavement in Four-Wheel-Drive High or
Four-Wheel-Drive Low for extended periods of time.
While driving on clean dry pavement and during tight
turns, you may experience a vibration in the steering
system.
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Shifting Into Four-Wheel Drive High or
AUTO (Automatic Four-Wheel Drive)
Turn the knob to the Four-Wheel High or AUTO position.
This can be done at any speed, except when shifting
from Four-Wheel Drive Low. The indicator light will ash
while shifting. It will remain on when the shift is
completed.
Shifting Into Two-Wheel Drive High
Turn the knob to the Two-Wheel 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 later in this
section for more information.
Shifting Into Four-Wheel Drive Low
When Four-Wheel Low is engaged, vehicle speed
should be kept below 45 mph. Extended high-speed
operation in 4L 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 NEUTRAL (N). The preferred methodfor 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 Four-Wheel Drive Low indicator light has stopped
ashing could damage the transfer case. To help
avoid damaging your vehicle, always wait for the
Four-Wheel Drive Low indicator light to stop ashing
before shifting the transmission into gear.
The vehicle may have signicant engagement noise and
bump when shifting between Four-Wheel Drive Low
and Four-Wheel Drive High ranges or from NEUTRAL
while the engine is 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.
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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, 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, 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 ashing and remain on before shifting your
transmission into gear.
Notice:Shifting the transmission into gear before
the Four-Wheel Drive Low indicator light has stopped
ashing could damage the transfer case. To help
avoid damaging your vehicle, always wait for the
Four-Wheel Drive Low indicator light to stop ashing
before shifting the transmission into gear.
The vehicle may have signicant engagement noise and
bump when shifting between Four-Wheel Drive Low
and Four-Wheel Drive High ranges or from NEUTRAL
while the engine is running.If the knob is turned to the Four-Wheel Drive High,
AUTO, or Two-Wheel Drive High switch position when
your vehicle is in gear and/or moving, the Four-Wheel
Drive High, AUTO 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 apply the regular brake
pedal. SeeParking Brake on page 2-42for more
information.
3. Start the vehicle or turn the ignition to ON/RUN.
4. Put the transmission in 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.
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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.
Shifting Out of NEUTRAL
To shift out of NEUTRAL do the following:
1. Set the parking brake and apply the regular
brake pedal.
2. Shift the transmission to NEUTRAL (N) and turn the
ignition to ON/RUN with the engine off.3. Turn the transfer case dial to the desired transfer
case shift position (Two-Wheel Drive High,
Four-Wheel Drive High, AUTO).
After the transfer case has shifted out of NEUTRAL
the NEUTRAL light will go out.
4. Release the parking brake prior to moving the
vehicle.
Notice:Shifting the transmission into gear before
the Four-Wheel Drive Low indicator light has
stopped ashing could damage the transfer case.
To help avoid damaging your vehicle, always
wait for the Four-Wheel Drive Low indicator light to
stop ashing 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.
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