1. Using an ohmmeter, check the circuit between the terminal and the sensor housing. If the circuit is open, replace the sensor.
2. Insert and lightly press a thick wire into the sensor channel. Check the continuity between the terminal and the sensor housing. If the circuit is open, replace the sensor.
3. Apply a vacuum of 49.0 kPa through the oil line opening and check the sensor circuit. If the circuit is open, it functions normally. Check for air leaks. If there are leaks, this means that the membrane is damaged and the sensor must be replaced.