Buy 2012 Gmc Sierra 3500 HD WT Extended Cab Pickup Fleetside 6.6L Duramax V8 DIESEL A/T 4WD Air Bag - OEM Gmc Part # 20884470

Sensor. Impact.
A Sensor to determine the location on the vehicle of Impact and the severity of the Impact to determine if and which air bags should be deployed. Air Bag. Assembly - INFL Rest SI IMP. Ft. Rollover. Side.

Air Bag Impact Sensor

Avalanche, Escalade EXT; All. Escalade ESV; All; 2nd Design. Front. Rear. Rear, all. SEDAN, front. SEDAN, rear. Silverado, Sierra. Silverado, Sierra Hybrid. Silverado, Sierra; Front. Silverado, Sierra; Rear; All. Tahoe, Yukon, Escalade; All. Tahoe, Yukon, Escalade; All; 2nd Design. Yukon XL, Suburban; All; 2nd Design.
Air Bag Crash Sensor - Repair or Replace
An airbag or SRS light can sometimes indicate a problem with the impact sensor on your 2012 GMC Sierra 3500 HD, particularly if it's been involved in a collision—at any speed. Have a technician inspect your vehicle's crash sensor.