GMC Sierra 2005 Owner's Manual page 79

United States
To turn off the right front passenger's airbag, insert
your ignition key into the switch, push in, and move
the switch to the off position.
The airbag off light will come on to let you know that
the right front passenger's airbag is off. The light
will stay on to remind you that the airbag is off.
The right front passenger's airbag will remain off
until you turn it back on.
Canada
CAUTION:
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If the airbag readiness light ever comes on
when you have turned off the airbag, it means
that something may be wrong with the airbag
system. The right front passenger's airbag
could inflate even though the switch is off.
If your vehicle is a regular cab pickup or an
extended cab pickup and this ever happens,
do not let anyone whom the national
government has identified as a member of a
passenger airbag risk group sit in the right
front passenger's position (for example, do not
secure a rear-facing child restraint in your
vehicle) until you have your vehicle serviced.
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