1. Check the continuity between the terminal and the case with an ohmmeter. If there is no continuity, replace the oil pressure sensor.
2. Check for continuity between the lead and body when inserting a thin wire into the sensor. If continuity is present, replace the sensor.
3. If there is no continuity when applying pressure of 50 kPa through the oil port, the sensor is working normally. Perform an air leak test. Air leakage indicates damage to the diaphragm. Replace it.