Fault code P0520 – a step-by-step guide to diagnosing and fixing it

Error code P0520 is displayed and the engine indicator light is on - what does this mean?

The OBD system detects a malfunction in the circuit of the oil pressure sensor or oil pressure switch. This DTC P0520 indicates problems with the oil pressure monitoring, which is crucial for engine protection. Slight variations in the interpretation of this fault code may occur with different manufacturers.

What causes can this error code have?

• Defective oil pressure sensor
• Damaged cable to the oil pressure sensor
• Corroded or loose plug connections
• Low oil level in the engine
• Clogged oil filter
• Defective engine control unit (ECM/PCM)
• Worn oil pump
• Short circuit in the wiring

What symptoms occur in parallel with fault code P0520?

• Engine indicator light: Lights up continuously or flashes
• Oil pressure warning light: May also be activated
• Engine noises: Unusual knocking or rubbing noises
• Loss of power: Reduced engine power as a protective measure
• Emergency running program: Engine switches to safety mode
• Starting problems: Difficult starting or prevented starting

How can the problem with error code P0520 be rectified?

• The repair requires a systematic diagnosis of the oil pressure monitoring.
• Check the oil level and oil quality and change if necessary, as low or contaminated oil levels are often the cause
• Remove the oil pressure sensor and replace with a new component if the sensor is defective
• Check the wiring to the oil pressure sensor for damage, corrosion or loose connections and repair them
• Change the oil filter if it is clogged and affects the oil pressure
• Test the oil pump for functionality and have it replaced if worn
• Check engine control unit and reprogram or replace if necessary