GMC 2010 Sierra 1500 Crew Cab Owner's Manual page 272

Some delay between the shifting and the light coming
on is normal.
See
information.
For more information, see
.
4-48
The four-wheel-drive light
comes on when a vehicle
with a manual transfer
case is shifted into
four-wheel drive and the
front axle engages.
for more
For vehicles with the tow/
haul mode feature, this
light comes on when the
Tow/Haul mode has been
activated.
When the ignition is on, the fuel gauge shows about
how much fuel is left in the fuel tank.
An arrow on the fuel gauge indicates the side of the
vehicle the fuel door is on.
The gauge will first indicate empty before the vehicle is
out of fuel, but the vehicle's fuel tank should be
filled soon.
When the fuel tank is low the FUEL LEVEL LOW
message appears. See
for more information.