2010 ML350 seat belt warning light won't go out
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Junior Member
Joined: Sep 2016
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2010 ML350
2010 ML350 seat belt warning light won't go out
Hi. Does anyone have any idea why this might be happening and how to fix it? In the past, when buckling the front seat belt the belt tensioner used to pull tight. Now the tensioner doesn't activate. I've noticed that seat belt light doesn't go out either. I'm thinking there is either a weight sensor in the seat or a sensor in the seat belt latch that isn't sensing correctly. The other consequence of this is that the seat belt warning tone goes off continually when moving. Any thoughts on what's wrong and the cost to fix? Thanks!
Thread Starter
Junior Member
Joined: Sep 2016
Posts: 25
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2010 ML350
Thanks Maj. Some additional information. I noticed there is a way to make the retractor work and the light go out. I noticed if I buckle the seat belt and then turn the ignition to position #2 and wait a second or two the retractor will work and the light will go out. If I turn the key all the way to start with out pausing the retractor won't work and the light will stay on. In addition, if I unbuckle the seat belt after to the car is running and then rebuckle it the light comes on, but won't go out. The retractor is an $800 part, so I want to make a sure it's the problem since it does work when I use the process above. Thanks!
Thread Starter
Junior Member
Joined: Sep 2016
Posts: 25
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2010 ML350
Looks like the passenger side seat belt doesn't pre-tension, but works correctly for turning seat belt warning light on and off. However, in the process of playing around I found out what the issue might be. It appears the issue is with the buckle. If I wiggle the seat belt while it's in the buckle the seat belt retracts, so looks like an issue with the buckle or a circuit that is created when the buckle is inserted. Still could be issue with seat belt if that's where the smarts is but I'm hoping the buckle. I believe there is also another sensor that is tied to the SRS system. Is it possible that sensor could be the issue? The fact that I can wiggle the seat belt when it's in the buckle to make it work is interesting. Thanks.
