The engine oil pressure sensor is used to detect the engine oil pressure and is usually screwed into the oil duct of the cylinder block. Its working principle is that the oil pressure sensor has a variable resistance inside, one end of which outputs signal and the other end is connected to the grounded sliding arm.

Oil pressure sensor: The engine oil pressure sensor is used to detect the engine oil pressure, which is usually screwed into the oil duct of the cylinder block. Its working principle is that the oil pressure sensor has a variable resistance inside, one end of which outputs signal and the other end is connected to the grounded sliding arm. When the oil pressure rises, the oil pressure pushes the diaphragm to bend through the lubricating oil channel interface, and the diaphragm pushes the sliding arm to move to the low resistance position, increasing the output current in the circuit; Instead, the diaphragm pushes the sliding arm to the high resistance position, reducing the output current in the circuit, and then using the pointer on the oil pressure gauge to indicate the oil pressure.

The switch of the engine oil pressure sensor is usually installed on the main oil circuit of the engine block to detect the engine oil pressure value. When the engine oil pressure is lower than a certain specified value, the engine oil pressure warning lamp turns on. When there is no oil pressure or low pressure, the spring pushes the diaphragm and cONtact is (on) closed; When the specified pressure is reached, the diaphragm overcomes the spring force and closes the contacts.

The indicator of the oil pressure sensor is installed in the combination instrument, and the pressure switch is installed in the engine lubricating oil circuit. In the pressure switch, there is a diaphragm acted by oil pressure and a contact acted by oil pressure. When the oil pressure is lower than the specified value, the diaphragm has no force to push the spring, the contact is closed and the indicator light is on; When the oil pressure is higher than the specified value, the diaphragm pushes the spring upward, the contact is separated, and the indicator light turns off to inform the driver that the oil pressure has reached the specified value. Under normal circumstances, the operating pressure of the contact is within the range of 30~50 kPa.

The detection method of the switch of the oil pressure sensor is as follows:

The oil pressure indicator does not illuminate after the ignition switch is turned on. The cause is that the harness of the oil pressure indicator falls off, or the filament is blown or the fuse is blown. When the engine is started, the oil pressure reaches the specified value and the oil pressure indicator is on. The fault is caused by abnormal operation of contact switch or grounding of harness.

Conditions that may occur if the oil pressure sensor is damaged:

The oil pressure signal shows that the engine oil pressure is lower than the specified value, and the engine control module considers it a fault and stores it in the form of fault code 415. At this time, because the oil pressure is too low, the protection function of the engine plays a role, forcing the engine power and speed to drop, which may cause the engine to shut down for protection. The oil pressure sensor is installed on the cylinder block.

The oil pressure indicator is normally on after startup. The engine fault lamp is always on. Idle speed, oil pressure value 0.99. Fault code: P01CA (oil pressure sensor voltage higher than upper limit)

Cause analysis: The oil pressure sensor probe is seriously damaged. ECU detects that the oil pressure sensor is not connected, and the instrument display value is the replacement value inside ECU.

Solution: Check the oil pressure sensor. If the short circuit display is OK, this means that your sensor is a normally open switch output. The switching value has only two states. If there is oil in the chassis, but the sensor still does not output, it indicates that the sensor is damaged. See if your sensor is dual? If it is a two-wire system, connect a small bulb (5-24v) to see if the bulb can light up. If it does not light up (with oil), it must be broken.