If your vehicle has a diesel engine GMC SIERRA CLASSIC 2007 Owners Manual
[x] Cancel search | Manufacturer: GMC, Model Year: 2007, Model line: SIERRA CLASSIC, Model: GMC SIERRA CLASSIC 2007Pages: 674, PDF Size: 3.5 MB
Page 137 of 674

Retained Accessory Power (RAP)
If the vehicle has Retained Accessory Power
(RAP), certain features will continue to operate for
up to 10 minutes after the ignition key is turned
to LOCK unless a door is opened.
Starting the Engine
Your vehicle has a Starter Motor Control. This
feature assists in starting the engine and protects
the electrical system. This feature may cause
the engine to crank even after the ignition key is
not in START.
Automatic Transmission
Move your shift lever to PARK (P) or
NEUTRAL (N). Your engine will not start in any
other position — that is a safety feature. To restart
when you are already moving, use NEUTRAL (N)
only. If you have a diesel engine refer to the
diesel supplement for the starting procedure.Notice:Do not 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.
Manual Transmission
The gear selector should be in NEUTRAL (N) and
the parking brake engaged. Hold the clutch
pedal to the oor and start the engine. Your
vehicle will not start if the clutch pedal is not all
the way down — that is a safety feature.
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Page 146 of 674

Low Traction Mode
(Allison Transmission®)
If your vehicle has the DURAMAX®diesel engine
and the Allison Transmission®,ithasaLow
Traction Mode that assists in vehicle acceleration
when road conditions are slippery, such as
with ice or snow. While at a stop, selecting the
second gear range using the Range Selection
system, will allow the Allison Transmission
®to limit
torque to the wheels after it detects wheel slip,
preventing the tires from spinning.
Notice:Spinning the tires or holding the
vehicle in one place on a hill using only the
accelerator pedal may damage the
transmission. The repair will not be covered by
your warranty. If you are stuck, do not spin
the tires. When stopping on a hill, use the
brakes to hold the vehicle in place.
Cold Weather Operation
(Allison Transmission®)
On cold days, approximately 32°F (0°C) or colder,
your automatic transmission is designed to shift
differently. The transmission uses a warm-up mode
shift schedule until the engine reaches normal
operating temperature. While the transmission is
in warm-up mode it is normal for transmission
upshifts to be delayed or held longer. This feature
improves heater performance by giving quicker
vehicle warm-ups.
When temperatures are below−13°F (−25°C), the
transmission will prevent certain operations to
protect against damage. When active the DIC will
display the message “Trans in Warm-up”.
SeeDIC Warnings and Messages on page 270for
more information.
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Page 149 of 674

Cruise Grade Braking is available on the 6.6L
DURAMAX®diesel engine. Cruise Grade Braking
monitors a vehicle’s cruise state, engine torque,
acceleration, vehicle speed, and the cruise set
speed. Using this information, it detects when the
truck is accelerating on a downhill grade and will
automatically downshift to slow the vehicle if it
exceeds the cruise set speed by a certain amount.
SeeCruise Control on page 217for more
information.
The Tow/Haul mode and Grade Braking shift
modes can be activated by pressing the button on
the end of the shift control stalk. If your vehicle
has the DURAMAX
®diesel Engine or the
8.1L VORTEC™ gasoline engine, Grade Braking
is only available while the Tow/Haul Mode is
selected. While in the Range Selection Mode,
Grade Braking is deactivated allowing the driver to
select a desired range of gears.
SeeAutomatic Transmission Operation on
page 140for more information.
Also seeTowing a Trailer on page 429for more
information.
Manual Transmission Operation
Five-Speed
(VORTEC™ 6.0L V8 Engine)
Here is how to operate
your transmission.
FIRST (1) is intended only for heavy loads or
trailer towing and is not recommended for normal
driving.
During the rst 500 miles (805 km) of vehicle use,
start your vehicle moving in FIRST (1). This
allows clutch components to break-in properly.
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Page 265 of 674

Here are some situations you may experience with
your fuel gage. None of these indicate a problem
with the fuel gage.
At the gas station, the fuel pump shuts off
before the gage reads full.
It takes a little more or less fuel to ll up than
the fuel gage indicated. For example, the
gage may have indicated the tank was half full,
but it actually took a little more or less than
half the tank’s capacity to ll the tank.
The gage goes back to empty when you turn
off the ignition.
If you have a diesel engine, see “Fuel Gage” in
the Diesel Engine Supplement.
Low Fuel Warning Light
The light next to the fuel gage will come on brie y
when you are starting the engine.
This light comes on when the fuel tank is low on
fuel. To turn it off, add fuel to the fuel tank.
SeeFuel on page 470.
Driver Information Center (DIC)
The Driver Information Center (DIC) display is
located on the instrument panel cluster, below the
speedometer. If your vehicle has DIC buttons,
they are located on the steering wheel. The DIC
can display information such as the trip odometer,
fuel economy, customization features, and
warning/status messages.
If your vehicle does not have DIC steering wheel
buttons, you will not have all of the features
listed. Scroll through the odometer, trip odometer,
engine hours, and selected range if your vehicle
has an Allison Transmission
®by pressing the
trip odometer reset stem located on the instrument
panel cluster. Turn off, or acknowledge, DIC
messages by pressing the trip odometer reset
stem. SeeSpeedometer and Odometer on
page 246for information on features for vehicles
without DIC buttons.
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