GMC 2011 Sierra - Manual (Page 362)

Black plate (68,1) GMC Sierra Owner Manual - 2011
9-68 Driving and Operating
Brakes
Antilock Brake
System (ABS)
This vehicle has the Antilock
Brake System (ABS), an advanced
electronic braking system that helps
prevent a braking skid.
When the engine is started and the
vehicle begins to drive away, ABS
checks itself. A momentary motor
or clicking noise might be heard
while this test is going on, and
it might even be noticed that
the brake pedal moves a little.
This is normal.
If there is a problem with ABS, this
warning light stays on. See Antilock
Brake System (ABS) Warning Light
on page 5‑28.
If driving safely on a wet road
and it becomes necessary to
slam on the brakes and continue
braking to avoid a sudden obstacle,
a computer senses that the wheels
are slowing down. If one of the
wheels is about to stop rolling,
the computer will separately
work the brakes at each wheel.
ABS can change the brake pressure
to each wheel, as required, faster
than any driver could. This can help
the driver steer around the obstacle
while braking hard.
As the brakes are applied, the
computer keeps receiving updates
on wheel speed and controls
braking pressure accordingly.
Remember: ABS does not change
the time needed to get a foot up to
the brake pedal or always decrease
stopping distance. If you get too
close to the vehicle in front of you,
there will not be enough time to
apply the brakes if that vehicle
suddenly slows or stops. Always
leave enough room up ahead to
stop, even with ABS.
Using ABS
Do not pump the brakes. Just hold
the brake pedal down firmly and let
ABS work. You might hear the ABS
pump or motor operating and feel
the brake pedal pulsate, but this is
normal.