1999 GMC Sonoma Owner's Manual - Page 35
1999 GMC Sonoma Manual
Page 35 highlights
yellowblue CAUTION: If the air bag readiness light ever comes on when you have turned off the air bag, it means that something may be wrong with the air bag system. The right front passenger's air bag could inflate even though the switch is off. If this ever happens, don't let anyone whom the national government has identified as a member of a passenger air bag risk group sit in the right front passenger's position (for example, don't secure a rear-facing child restraint in your vehicle) until you have your vehicle serviced. To turn the right front passenger's air bag on again, insert your ignition key into the switch, push in, and move the switch to the ON position. 1-29