Seatbelt tensions but doesn't let go ?
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From: Kalifornia
2012 Blk/Blk ML350 4Matic
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From: Connecticut
2018 BMW 540d
Never had that happen to me.Sounds like you might be behind on your payments! 
But seriously...that sounds like it's a potentially serious prob...I'd take it to the dealer ASAP.
But seriously...that sounds like it's a potentially serious prob...I'd take it to the dealer ASAP.
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From: Connecticut
2018 BMW 540d
Murphy's Law says that they won't be able to recreate it and their computer shows no faults.If that's the case hopefully they'll just believe you and replace whatever parts might be involved.
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2012 ML350
Of course, Murphy lives. Dealer found no faults and couldn't recreate (not surprising given that it only happens about 1 in 10 trips). When it happens again (I assume it will unless something with code scanning resets things and accidentally fixes it) we'll return it until they find the prob. Not a major issue when you're going slow, but it really concerns me when it happens on the highway.
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But then I can get a bit hot-headed at times.
Last edited by listerone; Jan 7, 2012 at 06:12 PM.
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Maybe PreSafe was triggered?
From the owner's manual
"If the hazardous situation passes without resulting in an accident, PRE-SAFE®
slackens the belt pretensioning. All settings made by PRE-SAFE®can then be reversed.
If the seat belts are not released:
Move the backrest or seat back slightly, but only when the vehicle is stationary.
The belt pretensioning is reduced and the locking mechanism is released."
From the owner's manual
"If the hazardous situation passes without resulting in an accident, PRE-SAFE®
slackens the belt pretensioning. All settings made by PRE-SAFE®can then be reversed.
If the seat belts are not released:
Move the backrest or seat back slightly, but only when the vehicle is stationary.
The belt pretensioning is reduced and the locking mechanism is released."
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2020 GLE 450; 2023 BMW M2 Coupe
Maybe PreSafe was triggered?
From the owner's manual
"If the hazardous situation passes without resulting in an accident, PRE-SAFE®
slackens the belt pretensioning. All settings made by PRE-SAFE®can then be reversed.
If the seat belts are not released:
Move the backrest or seat back slightly, but only when the vehicle is stationary. The belt pretensioning is reduced and the locking mechanism is released."
From the owner's manual
"If the hazardous situation passes without resulting in an accident, PRE-SAFE®
slackens the belt pretensioning. All settings made by PRE-SAFE®can then be reversed.
If the seat belts are not released:
Move the backrest or seat back slightly, but only when the vehicle is stationary. The belt pretensioning is reduced and the locking mechanism is released."
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MY17 E43 Matte Selenite/Macchiato Beige, MY16 GLE350d Tenorite/Crystal Grey, MY17 B250
Maybe PreSafe was triggered?
From the owner's manual
"If the hazardous situation passes without resulting in an accident, PRE-SAFE®
slackens the belt pretensioning. All settings made by PRE-SAFE®can then be reversed.
If the seat belts are not released:
Move the backrest or seat back slightly, but only when the vehicle is stationary.
The belt pretensioning is reduced and the locking mechanism is released."
From the owner's manual
"If the hazardous situation passes without resulting in an accident, PRE-SAFE®
slackens the belt pretensioning. All settings made by PRE-SAFE®can then be reversed.
If the seat belts are not released:
Move the backrest or seat back slightly, but only when the vehicle is stationary.
The belt pretensioning is reduced and the locking mechanism is released."
Thread Starter
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Posts: 121
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2012 ML350
Good thought, but it doesn't appear to be pre-safe. My wife said that there were no warning lights or sounds accompanying it. While she was driving the belt just suddenly tensioned up and stayed that way. She had to unclip the belt.
Does anyone (MBTech?) know if it should have stored some kind of incident of this? I would assume any activation of pre-safe would store something. Any other reason than pre-safe it would tension? Anything in the drowsy monitor? Other?
Thanks,
Does anyone (MBTech?) know if it should have stored some kind of incident of this? I would assume any activation of pre-safe would store something. Any other reason than pre-safe it would tension? Anything in the drowsy monitor? Other?
Thanks,
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seat belt tensioning
Good thought, but it doesn't appear to be pre-safe. My wife said that there were no warning lights or sounds accompanying it. While she was driving the belt just suddenly tensioned up and stayed that way. She had to unclip the belt.
Does anyone (MBTech?) know if it should have stored some kind of incident of this? I would assume any activation of pre-safe would store something. Any other reason than pre-safe it would tension? Anything in the drowsy monitor? Other?
Thanks,
Does anyone (MBTech?) know if it should have stored some kind of incident of this? I would assume any activation of pre-safe would store something. Any other reason than pre-safe it would tension? Anything in the drowsy monitor? Other?
Thanks,
"The belt strap is tightened slightly when:
R
you engage the belt tongue in the belt
buckle and you then turn the SmartKey to
position 2 in the ignition lock.
buckle and you then turn the SmartKey to
position 2 in the ignition lock.
R
the SmartKey is in position 2 in the ignition
lock and you then engage the belt tongue
in the buckle.
The seat-belt adjustment will apply a
retraction force if any slack is detected
between the occupant and the seat belt. Do
not hold on to the seat belt tightly while it is
adjusting. You can switch the seat-belt
adjustment on and off in the on-board
lock and you then engage the belt tongue
in the buckle.
The seat-belt adjustment will apply a
retraction force if any slack is detected
between the occupant and the seat belt. Do
not hold on to the seat belt tightly while it is
adjusting. You can switch the seat-belt
adjustment on and off in the on-board
computer (Y page 237)."
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seat belt tensioning
But it reads to me like if the seat belt tensioning is enabled, it will detect loose belts and tension accordingly. I thought it may be worth a try?
I was just reading through the manual in the last couple of day to familiarize, after I got my car back.
