GMC Yukon Denalid Owner's Manual page 110

If an airbag inflates, you will need to replace
airbag system parts. See the part on the airbag
system earlier in this section.
If the frontal airbags inflate you will also need to
replace the driver and front passenger's safety belt
retractor assembly. Be sure to do so. Then the
new retractor assembly will be there to help protect
you in a collision.
110
After a crash you may need to replace the driver
and front passenger's safety belt retractor
assemblies, even if the frontal airbags have not
deployed. The driver and front passenger's safety
belt retractor assemblies contain the safety belt
pretensioners. Have your safety belt pretensioners
checked if your vehicle has been in a collision,
or if your airbag readiness light stays on after you
start your vehicle or while you are driving. See
Airbag Readiness Light on page 229.