GMC 2012 Savana - Manual (Page 241)

Black plate (33,1) GMC Savana Owner Manual - 2012 - 2nd - 11/11/11
Driving and Operating 9-33
Drive Systems
All-Wheel Drive
If the vehicle has this feature,
engine power is sent to all four
wheels when extra traction is
needed. This is like four-wheel
drive, but there is no separate lever
or switch to engage or disengage
the front axle. It is fully automatic,
and adjusts itself as needed for road
conditions.
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 5‑24.
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.