GMC 2006 Sierra - Manual (Page 132)

Up-Shift Light
If you have a manual
transmission, you may
have a shift light. This light
will show you when to shift
to the next higher gear for
best fuel economy.
When this light comes on, you can shift to the next higher
gear if weather, road and traffic conditions allow. For the
best fuel economy, accelerate slowly and shift when the
light comes on.
While you accelerate, it is normal for the light to
go on and off if you quickly change the position of the
accelerator.
If your vehicle has four-wheel drive and is equipped with
a manual transmission, disregard the shift light when the
transfer case is in Four-Wheel Low.
Ignore the shift light when you downshift.
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.
To get the most satisfaction out of four-wheel drive, you
must be familiar with its operation. Read the part that
follows before using four-wheel drive. See the
appropriate text for the transfer case in your vehicle.
Front Axle Locking Feature
The front axle locks and unlocks automatically when
you shift the transfer case. Some delay for the axle
to lock or unlock is normal.
2-38