1996 GMC Safari Owner's Manual - Page 120

Have you recently changed brands of fuel? Oil Pressure Gage The oil pressure gage shows the engine oil pressure in psi (pounds per square inch) when the engine is running. If so, be sure to fuel your vehicle with quality fuel (see "Fuel" in the Index). Poor fuel quality will cause your engine not to run as efficiently as designed. You may notice this as stalling after start-up, stalling when you put the vehicle into gear, misfiring, hesitation on acceleration or stumbling on acceleration. (These conditions may go away once t.he engine is warmed up.) This will be detected by the system and cause the light to turn on. I f you experience this condition, change the fuel brand you use. It will require at least one full tank of the proper fuel to turn the light off. 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. 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. 2-60