Fault code P250B is called “Engine Oil Level Sensor Circuit Range/Performance” but in different programs it may be called differently. This fault designation applies to all vehicles equipped with OBD-II.
Technical description and explained code P250B
OBD-II fault code P250B is a generic fault code defined as “Engine oil level sensor circuit performance range mismatch”. It is set when the Powertrain Control Module (PCM) detects a fault in the circuit or the engine oil level sensor itself.
The engine oil level gauge is designed to monitor the level so that the proper amount of lubrication is provided to the internal engine components. In most cases, the engine oil level gauge is installed on or inside the engine oil pan.
All major car manufacturers recommend monitoring the level and changing the engine oil at least once a year. Even if the distance traveled is significantly less than recommended.
When the PCM detects improper voltage or resistance in the engine oil level sensor circuit, code P250B is set and the Check Engine light may illuminate. In some cases the PCM may shut down the engine to prevent damage to internal components.
Symptoms of vehicle malfunctions
The main signal that an error P250B has occurred is the Malfunction Indicator Lamp (MIL) is also known as the CheckEngine Light.
It can also be warning signs such as:
- The “Check engine” control lamp on the control panel will light up (the code will be written in the memory as a fault).
- The low oil pressure indicator light may illuminate.
- Oil check message.
- Bad engine start, or complete failure to start.
Error P250B related to oil level and pressure is considered serious and is recommended to be corrected as soon as possible. Insufficient or poor lubrication can cause irreversible internal engine damage.
Factors that can cause this error code
The error code P250B can mean that one or more of the following problems have occurred:
- Oil level sensor is defective.
- Oil pressure sensor is dirty or clogged.
- Oil change interval exceeded.
- Low engine oil level.
- High engine oil level.
- Faulty or damaged wiring.
- Corroded, damaged, or loose connector.
- Blown fuse or fusible link.
- Sometimes faulty PCM module is the cause.
How to fix or reset OBD-2 code P250B
Some suggested steps for troubleshooting and fix the error code P250B:
- Read all data and stored error codes, using an OBD-II scan tool.
- Clear the codes and check if error code P250B appears again.
- Check the engine oil level and condition. If necessary, replace the oil along with the filter.
- Check connection wiring and connectors and fuses.
- Inspect the oil level sensor.
- Check the sensor with a digital multimeter, and replace it if necessary.
- Pay attention to mechanical wear and tear on the engine. Physically check the oil pressure with a mechanical pressure gauge.
Diagnose and repair of problems
Check that the oil level is at the proper level, that it is not diluted with fuel or coolant, and that it is not of a thick, tarry consistency. If necessary, refill or replace the oil before proceeding with further diagnosis.
Perform a thorough visual inspection of the wiring to look for damaged, burned, disconnected, shorted, or corroded wires and connectors. If necessary, repair, clear code P250B and re-scan the system to see if the code returns.
Check the wiring with a multimeter
After no visible damage is found, check the oil level sensor for resistance, ground and reference voltage. Compare all readings with those in the manual. If necessary, replace the wiring to make sure all readings are in accordance with the manufacturer’s specifications.
Remember to disconnect the oil level sensor from the PCM during the resistance and continuity check to prevent damage to the controller.
Oil pressure check
It is necessary to make sure that the oil pressure is within the range specified by the manufacturer, this can be done by attaching a pressure gauge to the engine. Using a scanner is not recommended because the scanner uses the same information as the PCM.
The PCM and the scan tool may indicate an oil pressure condition that is based on incorrect data.
It may take a few seconds for the gauge to record a reading, but after about ten seconds it should stabilize. Record the reading and compare it to the value in the manual.
Allow the engine to warm up, watching the gauge reading. As the engine warms up, there may be a slight drop in pressure indicated by the pressure gauge. But oil pressure should not drop below the minimum specified value when the engine is at operating temperature.
Oil pressure readings that fall below the acceptable lower limits indicate excessive wear or other mechanical problems inside the engine. In this case, simply replacing the oil quality sensor will not solve the P250B error.
On which vehicles does this problem occur most frequently
Fault code P250B can occur on different vehicles but there are statistics on which brands this occurs most often. Here is a list of some of them:
- Acura
- Citroen
- Fiat
- Honda (Civic)
- Hyundai (Santa Fe)
- Kia (Sorento, Sportage)
- Mitsubishi (Outlander)
- Peugeot (207)
- Volvo
Fault code P250B can sometimes be found with other errors. The most common are the following: P250A, P250C, P250D, P250E, P250F.
