1998 GMC Sonoma Owner's Manual - Page 126

If you experience one or more of these conditions, change the fuel brand you use. It will require at least one full tank of the proper fuel to turn the light off. Oil pressure may vary withengine speed, outside temperature and oil viscosity, but readings above the low pressure zone indicate the normal operating range. If none of the above steps have made the light turn off, have your dealer or qualified service center check the vehicle. Your dealer has the proper test equipment and diagnostic tools to fix any mechanical or electrical problems that may have developed. A reading in the low pressure zone may be caused by a dangerously low oil level or other problems causing low oil pressure. Engine Oil Pressure Gage I The oil pressure gage shows the engine oil pressure in psi (pounds per square inch) when the engine is running. /d CAUTION: Don't keep drivingif the oil pressure is low. If you do, your engine can become hot that it so catches fire.You or others could be burned. Check youroil as soon as possible and have your vehicle serviced. NOTICE: Canadian vehicles indicate oil pressure in kPa (kilopascals). Damage to your engine from neglected oil problems can be costly and is not covered by your warranty. 2-62