1. Disconnect the ground cable from battery.
2. Remove the oil pressure switch. 
3. Attach the oil pressure gauge to the cylinder block.
4. Connect the ground cable to battery.
5. Start the engine, and measure the oil pressure.
NOTE:
• Standard value is based on an engine oil temperature of 80°C (176°F).
• If the oil pressure is out of specification, check oil pump, oil filter and lubrication line.
• If the oil pressure warning light is ON and oil pressure is within specification, check the oil pressure switch.
Engine oil pressure:
Standard
98 kPa (1.0 kgf/cm2, 14 psi) or more (at 600 rpm)
294 kPa (3.0 kgf/cm2, 43 psi) or more (at 5,000 rpm)
6. After measuring the oil pressure, install the oil pressure switch.