Mercedes A Klasse Oil Temperature Warning

I had a similar issue with my old Renault a few years back. The sensor was throwing codes and the dash lit up. Did you check the sensor's wiring harness for any signs of damage or corrosion? That was the culprit in my case; a broken wire.

I am suspecting the oil temperature sensor. Was the oil pressure warning lamp also active in your case?

Yes, the oil pressure light came on intermittently too. I replaced the sensor myself, but the light persisted until I found the broken connection. I'd suggest checking the wiring thoroughly before replacing the sensor. If it is not the wiring or plug connection, visit a workshop.

I checked it out. Inspection revealed a corroded connector. Replacement done for 95€. Issue resolved. Thank you.