Antilock Brake System (Abs); Warning Light; Four-Wheel-Drive Light; Tow/Haul Mode Light - GMC Sierra 2018 Owner's Manual

150 Instruments and Controls
Antilock Brake System
(ABS) Warning Light
This light comes on briefly when the
engine is started.
If the light does not come on, have it
fixed so it will be ready to warn if
there is a problem.
If the light comes on while driving,
stop as soon as it is safely possible
and turn off the vehicle. Then start
the engine again to reset the
system. If the ABS light stays on,
or comes on again while driving, the
vehicle needs service. A chime may
also sound when the light comes on
steady.
If the ABS light is the only light on,
the vehicle has regular brakes, but
the antilock brakes are not
functioning.
If both the ABS and the brake
system warning light are on, the
vehicle's antilock brakes are not
functioning and there is a problem
with the regular brakes. See your
dealer for service.
See Brake System Warning Light
0 149.

Four-Wheel-Drive Light

The four-wheel-drive light comes on
when the manual transfer case is
shifted into four-wheel drive and the
front axle engages. LO or HI will
also be next to this light when the
vehicle is in four-wheel low or
four-wheel high.
Some delay between the shifting
and the light coming on is normal.
See Four-Wheel Drive 0 262.

Tow/Haul Mode Light

For vehicles with the Tow/Haul
Mode feature, this light comes on
when the Tow/Haul Mode has been
activated.
See Tow/Haul Mode 0 261.

Hill Descent Control Light

If equipped, the Hill Descent Control
light comes on when the system is
ready for use. When the light
flashes, the system is active.
See Hill Descent Control (HDC)
0 274.