One problem related to air bag has been reported for the 2005 GMC Sierra. The most recently reported issues are listed below.
Power steering stops working on slow right hand turns. I sometimes need to back up in order to complete the turn. I also end up crossing into oncoming lanes if no traffic is comeing towards me. If there is traffic I need to stop in the middle of the turn until the traffic clears. The "check airbag" light came on at 85000 miles after the battery discharged from the vehicle sitting to long without being driven.