M Klasse Engine Oil Temperature Warning Light

My 2002 Mercedes M Klasse with a gasoline engine, only 36777 km, has the engine oil temperature warning light showing on the speedometer. Car diagnostics show an error related to the engine oil temperature sensor and the oil pressure warning lamp lights up sometimes. I suspect a dodgy cable or plug connection to the sensor. Has anyone seen this before?

4 comment(s)

Sounds familiar. I had a similar issue with my M Klasse. Same symptoms: warning light, error code. Check the wiring harness near the temperature sensor, especially the connector. It could be corroded or loose. Is the engine temperature sensor reading correctly?

I'll check the harness. By engine temperature sensor, do you mean the coolant temperature sensor? Where is the engine oil temperature sensor located? Is it difficult to get to?

Yes, I meant the coolant temperature sensor. If that's reading okay, and the oil pressure is fine, it's likely just the sensor or wiring. If you aren't comfortable tracing wires, I'd take it to a workshop. Could save you hassle.

I checked the wiring and couldn't find anything obvious, so I took it to a shop. They confirmed it was a faulty connection at the temperature sensor, like we suspected. Total bill was 95€, including diagnostics. Annoying, but glad it's sorted.

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