P0521: Engine Oil Pressure Sensor/Switch Range/Performance

What does the P0521 error code mean?

The P0521 diagnostic trouble code indicates "Engine Oil Pressure Sensor/Switch Range/Performance." The oil pressure sensor monitors the engine's oil pressure to ensure proper lubrication and protect engine components from damage. This code is triggered when the engine control module detects oil pressure sensor readings that are outside the expected range or inconsistent with actual engine conditions.

Why it's important to address the P0521 error code

Accurate oil pressure readings are critical to maintaining proper engine lubrication. If the oil pressure is incorrect, it can lead to insufficient lubrication, overheating, and severe damage to internal engine components. Even if the problem is related to the sensor itself, ignoring this warning can result in costly repairs if an underlying issue goes unaddressed.

Can I safely drive my car with this error code?

It is not recommended to drive your car with the P0521 code. This code may indicate a sensor issue or a more severe problem with oil pressure. Driving with insufficient oil pressure can cause catastrophic engine damage. If the oil pressure warning light is on or the engine is making unusual noises, stop driving immediately and address the issue.

Common symptoms of the P0521 error code

• Illuminated check engine light

• Oil pressure warning light activated on the dashboard

• Engine running rough or making unusual noises

• Decreased engine performance

• Possible stalling

How to diagnose the P0521 error code

Diagnosing the P0521 code involves the following steps:

• Scan for codes: Use an OBD-II scanner to confirm the P0521 code and check for related codes.

• Inspect oil levels: Check the oil level and condition to ensure proper lubrication.

• Inspect the oil pressure sensor: Examine the sensor and its wiring for damage, corrosion or disconnections.

• Test oil pressure: Use a mechanical oil pressure gauge to verify the actual oil pressure against the sensor's readings.

• Inspect the oil pump: Assess the oil pump's performance to ensure it is providing adequate pressure.

• Check for internal engine issues: Look for potential blockages or wear in the oil passages that could affect pressure.

How to repair the P0521 error code

Repairing the P0521 code typically involves:

• Replacing a faulty oil pressure sensor or switch.

• Repairing or replacing damaged wiring or connectors in the sensor circuit.

• Changing the engine oil and oil filter if the oil is dirty or contaminated.

• Addressing issues with the oil pump, such as replacement or repair, if needed.

• Clear the code and perform a test drive to confirm that the issue is resolved.

More information on OBD-II diagnostic trouble codes

On-board diagnostics (OBD-II) and diagnostic trouble codes are part of your car's self-diagnostic system. The five-character alphanumeric code identifies the part and problem. Check out Edmunds’ growing database of diagnostic trouble code information here.