Opel - oil pressure warning lamp comes on sporadically - error code P0523

With the above-mentioned vehicle model, it can happen that the oil pressure warning lamp lights up from time to time.

The error code P0523 'Engine oil pressure sensor − circuit faulty' is also stored in the engine control unit.

In this case, the oil pressure sensor, oil pressure switch, oil pump and oil pressure control valve should all be checked first.

If no mechanical fault is found in the lubrication system, a possible cause could be an electrical fault in the power supply to the engine control unit.

Increased contact resistance or a corroded earth connection can cause signal interruptions in the sensor circuit, which may be mistakenly detected as a fault in the oil pressure system.

Once all mechanical causes have been ruled out, a targeted check of the power supply and ground supply to the engine control unit is required for further diagnosis. Particular attention should be paid to the ground screw connection in the area of the left suspension strut dome. An oxidised or corroded connection can cause irregular voltage drops.

In this context, the earth connection should be checked, cleaned and then treated with a preservative.