General Motors is recalling 40,683 cars and pickup trucks because their front air bags or seat belt pretensioners might fail to deploy if a crash occurs, according to the National Highway Traffic Safety Administration.

The recall covers 2014-2016 Buick Lacrosse, Chevrolet Spark EV, Chevrolet Caprice PPV and Chevrolet SS vehicles; 2014-2017 Buick Encore, Chevrolet Corvette, Chevrolet Silverado 1500 and GMC Sierra 1500 vehicles; 2015-2016 Cadillac Escalade and Escalade ESV, Chevrolet Tahoe, Chevrolet Trax, Chevrolet Suburban, Chevrolet Silverado 2500 and 3500, and GMC Yukon and Yukon XL vehicles; and 2015-2017 GMC Sierra HD 2500 and 3500 pickup trucks.

All of these vehicles were part of a previous recall, but some of them might not have received the complete software update needed to fix the problem, NHTSA said.

“Without the update, certain driving conditions may cause the air bag sensing and diagnostic module (SDM) software to activate a diagnostic test,” NHTSA explained on its website. “During this test, deployment of the frontal air bags and the seat belt pretensioners would not occur in the event of a crash.”

GM dealers will reflash the SDM software to resolve the issue. Vehicles that have had a previous air bag deployment will have the SDM replaced. These repairs will be performed free of charge.

Vehicle owners can reach Buick customer service at (800) 521-7300, Cadillac customer service at (800) 458-8006, Chevrolet customer service at (800) 222-1020, and GMC customer service at (800) 462-8782. GM's number for this recall is 17287.