Mercedes M Klasse Hybrid Knock Sensor Issue

A defective knock sensor could cause those symptoms. I had a similar issue with my old BMW 3 series. The warning light illuminated and the engine was not running smoothly. It turned out to be a corroded connection. Before you replace the sensor, has anyone checked the wiring and connector for damage or corrosion?

That's interesting. You mentioned corrosion. Should I check for something specific? Is there a particular area where such problems usually occur?

Think of it like a garden hose. If the hose kinks, you won't get water. Same with wiring. Check for breaks, kinks, or areas where the insulation is worn away. The connector itself might have some green gunk (corrosion) inside. But this is probably something best left to a workshop; they have tools to properly diagnose the issue.

Thanks a lot for your advice. I spoke to the workshop, and they confirmed it was a faulty connection, just like you suspected. They cleaned everything, and now the car runs like new again. I appreciate the help.