GMC 2009 Sierra - Manual (Page 27)

Q:
What is wrong with this?
A:
The belt is twisted across the body.
{ CAUTION:
You can be seriously injured by a twisted belt.
In a crash, you would not have the full width of
the belt to spread impact forces. If a belt is
twisted, make it straight so it can work
properly, or ask your dealer/retailer to fix it.
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