POST UPDATED IN May, 2023
Oil Pressure Sensor
The Oil Pressure Sensor is a kind of barometer in charge of measuring the vehicle’s engine oil pressure, then sends a signal to the computer to check the engine lubrication status. It measures the oil pressure from the engine main driver until it is distributed by the oil pump.
What is the Oil Pressure Sensor?
Also known as oil bulb, it is a component composed of an electronic connection fixed with a screw to the engine. It has a contact or warning indicator which informs if the oil pressure limit is reached.
What is the Oil Pressure Sensor used for?
The OPS Sensor serves to measure the oil flow pressure that is circulating in the engine. Specifically, it does so very close to the impulse point, so that the measurement is as efficient and accurate as possible. This sensor externalizes the alert in case of internal lubrication deficiency.
How does the Oil Pressure Sensor work?
The operation of the OPS sensor involves the principle of atmospheric pressure. The force exerted by the oil flow on the bulb or metal tip of the sensor causes a signal to be generated in the sensor. This voltage is sent to the ECU and if there is a pressure drop, it will be detected in the cluster by the red visual indicator in the form of a light bulb.
If the sensor is a variable resistance sensor, the pressure will affect the current generated in the circuit. On the vehicle’s instrument panel there will be a gauge with a scale to indicate how much oil pressure is present. In the end the principle is electromechanical.
Types of Oil Pressure Sensor
Depending on the manufacturer and the year of production of your vehicle, you can find at least two types of oil pressure sensor. There is the analog signal one and the platinum one:
Analog signal OPS sensor
In this model, if the oil pressure is higher or increasing, there is more internal resistance. However, if the pressure drops, the resistance decreases. So, the higher the pressure the higher the voltage and the lower the pressure the lower the voltage. This variation is interpreted by the engine ECU.
Platinum sensor
In this type of OPS sensor, the structure is bulb. The pressure exerted on the bulb keeps open small cells. If the pressure drops to an allowable minimum, they close. This action causes the oil pressure indicator light to come on in the cluster.
Depending on some other electronic characteristics of the vehicle, the ECU may command the engine to shut down as a protective measure to prevent further damage.
Oil Pressure Sensor Failures
The OPS sensor is a very reliable component. Its mechanism and operation is not so much conditioned to the electronics and other vehicle systems, as other sensors. Practically, if the warning light on the dashboard comes on, it is an indication that you should turn off the engine and proceed to a specialized workshop for a check-up.
Throughout the engine there are small ducts and holes through which the oil circulates. Thanks to the pressure of the pump, the lubricant penetrates through all of them and reaches the necessary points to avoid metal-to-metal friction. If there is not the required pressure, the alarm is raised, since running without oil will damage the engine to such an extent that you could lose it completely.
Causes of the oil pressure light coming on
While it is true that the sensor could fail, the causes are usually associated with other elements. Any of these will put the circuit on alert:
Oil pump
Oil pumps suffer wear after a certain mileage. Their useful life, too, comes to an end and the decrease in pressure or intermittent failures will begin to be noticed. This will cause the warning light to come on. So, there is no other option but to replace the pump.
Internal and external filter element
Every hydraulic or oil lubrication system has a filter element. In the case of combustion engines, there are two. An internal one at the bottom of the crankcase, from where the pump sucks the oil, this is a mesh that filters the impurities. While the external one filters the oil after it has passed through the engine.
Any of the two that becomes clogged can generate a drop in oil pressure.
Condition of the oil
There are lubricants that due to their low quality tend to evaporate, others lose their viscosity grade. These are two factors that alter the correct oil pressure on the sensor. Also, there could be a loss of oil due to leaks, to the point of not being able to operate the engine.
OBD2 codes related to the OPS Sensor
The fault codes that can be generated by problems in the Oil Pressure Sensor are as follows:
- P0520: Circuit malfunction.
- P0521: Value out of expected level.
- P0522: Oil pressure low.
- P0523: Oil pressure high.
- P0524: Oil pressure too low.
How to test the OPS sensor?
It is important, before checking the condition of the pressure sensor, to check the oil level of your engine. The steps are quite basic:
- Locate the sensor and have a tool handy to disconnect it.
- Turn the key in the switch to ON, without starting the engine.
- Gradually unscrew or disconnect the OPS sensor and have someone else tell you if the light on the dash comes on. This is an indication that your sensor is indicating.
- Also, you can remove the sensor and place a pressure gauge of the same thread.
- There, you start the engine and check for a reading between 40 and 60 psi. If at that pressure the dashboard light comes on, your OPS sensor requires replacement.
How to clean the Oil Pressure Sensor?
The oil pressure sensor is not a maintenance required component. You really don’t do much if you try to clean the sensor. It is good to perform the recommended tests and some checking of the wiring and connector. So, when it fails, the best thing to do is to replace it.
Finally, good maintenance of your vehicle includes oil changes at the recommended mileage. This is one of the best measures to preserve your engine and its components. If at any time you see the light bulb on your dashboard, do not ignore this warning, it means that the durability of your engine is at risk.
Where is the OPS sensor in your vehicle?
For engines with 6 or more cylinders, you can find it on the side, below the spark plug line. If the car has a 4-cylinder engine, you should look at the lower part, at the starter location. Nearby, you will surely find it. You can find out the exact location of the OPS sensor by acquiring the car’s electrical diagrams.
