Here we will discuss the following engine sensor: the oil pressure sensor (or oil pressure switch). We’ll go over the sensor’s functions and common symptoms to look for with a bad oil pressure sensor.
How an oil pressure sensor or switch works
The main job of an engine oil pressure sensor is to track the oil pressure in the vehicle and then send that information directly to the combination gauge or dashboard.
If the vehicle has an electronic control module (almost all do), the oil pressure switch will send this information to the module when it can be calculated.
Once calculated, the information is sent to the instrument cluster or dashboard so that the engine oil pressure warning light or oil pressure gauge can be activated.
Symptoms Related to Faulty Alternator or Oil Pressure Sensor
If there is a problem with the oil pressure sensor, it will usually trigger the engine oil pressure light. It could also cause an inaccurate reading on the oil pressure gauge. Below are the three most typical signs of a faulty pressure switch or oil pressure sensor:
#1 – Oil pressure light flashes again
Sometimes, if the oil pressure sensor is not working properly, the low oil light will flash on the dashboard. This can cause a driver to panic, as they will believe their oil level is low, which, if true, could damage the engine.
To determine whether this is a real warning or not, you must manually check the oil level to see if it is low. Otherwise, you may have a faulty oil pressure sensor and will need to replace it immediately.
Related: Common Signs of Low Motor Oil
#2: Indicates an incorrect reading on the oil pressure gauge
If you drive an older vehicle, there is likely a mechanical gauge that calculates oil pressure. Whenever the oil levels are normal but the dipstick reads zero, it means that the oil pressure sensor needs to be replaced because it is faulty or there is some kind of connection problem.
If you drive a modern vehicle, your oil pressure gauge is probably electronic and sends an electronic signal to get the reading.
Whenever an oil pressure sensor malfunctions in a modern car, the gauge will have strange readings or remain full or zero. Check the sensor wiring and replace it if necessary.
Don’t assume your engine’s oil level is low without physically checking the dipstick. Otherwise, you risk ending up with too much oil in your engine, which can lead to a host of problems, including high oil pressure.
See also: code P0523
#3 – Oil pressure light comes on
The best way to test if your sensor is faulty is by measuring the oil pressure lights. If the low oil pressure warning light comes on when engine oil levels are normal and your engine runs smoothly and quietly, you probably have a faulty oil pressure sensor. When this sensor is faulty, it will give you false readings.
If your oil levels are normal but you hear grinding, ticking, or other noises from your engine, you have a real oil pressure problem, such as a faulty oil pump, and the sensor is just working.
Eventually, these readings will go well beyond normal specifications, causing the warning light to come on. At this point, you should replace your sensor to stay properly informed about your oil pressure level.