GMC 2010 Terrain Owner's Manual page 115

Do not keep driving if the oil
pressure is low. The engine can
become so hot that it catches fire.
Someone could be burned. Check
the oil as soon as possible and
have the vehicle serviced.
The oil pressure light should come
on briefly as the engine is started.
If it does not come on have the
vehicle serviced by your dealer/
retailer.
If the light comes on and stays on, it
means that oil is not flowing through
the engine properly. The vehicle
could be low on oil and might have
some other system problem. See
your dealer/retailer.
For vehicles with the fuel economy
mode light, it comes on when the
eco (economy) switch, located on
the center console near the shifter,
is pressed. For vehicles with a
Driver Information Center (DIC) an
ECO Mode On message displays.
See
for more information.
Press the switch again to turn
off the light and exit the fuel
saver mode.