Mercedes ML Knock Sensor Issue

My 2001 Mercedes ML with a gasoline engine is throwing me for a loop. The check engine light is on, and my fuel efficiency has gone down. The engine's idling rough. I've scanned it and it's showing a knock sensor defective. I'm suspecting it's just a dodgy cable or plug connection. Has anyone else dealt with this? I'm trying to avoid a costly repair, especially since I read the repair might cost around 95€. Any insights on tackling this before I bite the bullet and take it in?

4 comment(s)

Sounds familiar. I had a similar issue with my ML. Knock sensor problems can really mess with the ignition timing and cause poor performance. Check those connections like you said. Could save you a trip.

Thanks, that's encouraging! When you say check the connections, anything specific I should be looking for? I've wiggled the plugs, but is there a common failure point or anything I should be testing with a multimeter?

Honestly, I just took mine to the workshop when it happened. They sorted it quick. If you're not sure, might be worth doing the same.

Appreciate the advice! Took it to the shop, and you were spot on. It was a corroded connector on the knock sensor. They cleaned it up, cleared the warning light, and it's running smooth again. Thanks for the help!

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