Mercedes R Klasse knock sensor issue

A defective knock sensor can indeed cause those symptoms The engine control unit relies on the knock sensor to detect engine knock or pinging If the sensor malfunctions, the ECU may retard the timing excessively, leading to reduced fuel efficiency and rough idling Have you inspected the wiring and connector to the knock sensor for any signs of damage or corrosion

I checked the wiring, but it's cramped, and I couldn't see well Is there a common spot on the connector or wiring harness that fails Any tips for a better look without taking apart the engine

While there aren't specific 'hot spots' known to fail, focus on areas where the wiring may rub against engine components or where the connector is exposed to the elements Given the symptoms and the error code, and if you are not comfortable with a detailed inspection, it might be prudent to have a qualified technician diagnose the issue to confirm the cause before replacing parts This could save you time and money

I took it to a workshop, and it was the knock sensor After installing a new sensor, the warning light is off, the engine is running smoothly, and fuel consumption is normal Thanks