Frequently Asked Question
Oil Pressure is Inaccurate
Last Updated 2 years ago
Cause:
- The wrong oil pressure sensor is being used with a particular model of the EIS.
- The ground connection to the pressure sensor is not good.
- The engine actually has this pressure.
Troubleshooting
- See the “Background” section of the Oil Pressure section to verify the sensor type matches with the EIS instrument type.
- With the EIS turned on, measure the voltage between the case of the oil pressure sensor, and the case of the EIS (the metal edge of the faceplate can be used). This voltage should be less than 0.1 volts. The stainless steel overbraid of a hose is usually not a good source of ground for the sensor. The sensor should be mounted to a manifold that is grounded.
- Occasionally we hear from a customer that they think the EIS oil pressure is inaccurate when they are reading very low oil pressure, and it turns out that this is not true. Don't assume this is an instrumenation problem. Verify the pressure with another oil pressure gauge. This can also be done by replacing the oil pressure sensor with a new VDO 150 psi sensor, and measuring the resistance of this sensor with a known good ohm meter. The pressure can be calculated by as follows: Pressure = (ohms – 10)/1.2