Fault code P0523 – a step-by-step guide to diagnosing and fixing it

Error code P0523 is displayed and the check engine light is on - what does this mean?

The OBD/EOBD system has detected that the engine oil pressure sensor is reporting a signal that is too high. This DTC P0523 indicates that the measured oil pressure is above the expected range or that the sensor itself is defective. For some manufacturers, this fault code may also be referred to as "Engine Oil Pressure Sensor/Switch High Input".

What can cause this error code?

• Defective oil pressure sensor
• Clogged oil filter
• Engine oil too viscous
• Damaged wiring to the oil pressure sensor
• Corroded or loose plug connections
• Defective engine control unit (ECU)
• Mechanical problems in the oil pump
• Blocked oil lines
• Incorrect oil viscosity

What symptoms occur in parallel with fault code P0523?

• Check engine light: The check engine light illuminates continuously
• Oil pressure warning: Additional warning lights in the dashboard can be activated
• Engine power: Reduced engine power due to emergency running program
• Engine noises: Unusual knocking or rattling noises when the actual oil pressure is low
• Starting problems: Difficulty starting the engine in severe cases
• Oil consumption: Increased oil consumption due to mechanical defects

How to fix the problem of trouble code P0523?

• Repairing trouble code P0523 requires a systematic diagnosis of the oil pressure system.
• Replace and calibrate the oil pressure sensor, as this is most frequently responsible for the faulty signal
• Check the wiring and plug connections to the oil pressure sensor, clean or replace if corroded or damaged
• Change the oil filter and fill with fresh engine oil of the correct viscosity to remove blockages
• Measure the mechanical oil pressure with a pressure gauge and repair the oil pump or pressure valve if there are deviations
• Check engine control unit for software errors and reprogram or replace if necessary
• Flush the oil circuit if there are blockages in the oil lines and then carry out a complete oil change