2003 GMC Sonoma Owner's Manual - Page 164

Oil Pressure Gage Don't keep driving if the oil pressure is low. If you do, your engine can become so hot that it catches fire. You or others could be burned. Check your oil as soon as possible and have your vehicle serviced. I United States Canada Nofice: Damage to your engine from neglected oil is problems can be costly and not covered by your warranty. 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. 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). 3-37