The Office of Defects Investigation (ODI) has received fifteen consumer complaints on alleged air bag system malfunctions on certain General Motors (GM) vehicles. Nine of the consumer complaints allege the illumination of an air bag malfunction indicator (MIL). Six crash incidents have significant frontal collision damage where driver frontal air bags failed to deploy. Additionally, all the complaints received by ODI involve either GM vehicles (Model Years 2020 and 2021 Silverado, Sierra, Tahoe, Suburban, Yukon, Yukon XL, Escalade, and Escalade ESV) covered by GM Technical Service Bulletin (TSB) 21-NA-005 or CT4, CT5, and XT4 vehicles. The TSB, issued in March 2021, addresses air bag MIL illumination accompanied by diagnostic trouble codes B0001-1B or B0012-0D.It also cites rust particles in the connection terminal interface of the driver air bag inflator as the cause of the air bag MIL illumination.Illumination of the air bag MIL under these circumstances may result in a non-deployment of the driver airbag during a frontal collision and increased risk of injury to the driver.ODI is opening this preliminary investigation to determine the scope and severity of the potential problem and to fully assess the potential safety-related issues.The ODI reports cited above are available for review at NHTSA.gov under the following identification numbers: 11339175, 11343883, 11360339, 11361893, 11362218, 11362839, 11363479, 11363644, 11374129, 11376429, 11384282, 11385267, 11385428, 11390093, 11395340.