GMC 1994 Sonoma Owner's Manual page 108

Oil Pressure Gage
The oil pressure gage shows the engine oil pressure in psi (pounds per
square inch) when the engine is running. Canadian vehicles indicate
pressure in kPa (kilopascals). Oil pressure may vary with engine speed,
outside temperature and oil viscosity, but readings above the low pressure
zone indicate the normal operating range.
A reading in the low pressure zone may be caused by a dangerously low oil
level or other problems causing low oil pressure.
NOTICE:
Damage to your engine from neglected oil problems can be
costly and is not covered by your warranty.
Indicator Lights
Indicator lights go on when you use your turn signals, change from low
beam headlights to high beams, or when you use your hazard flashers. The
next few pages will also tell you about
the
indicator lights on your vehicle
and help you locate them.
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