General Motors is recalling nearly 400,000 full-size pickup trucks and SUVs used in government fleets as well as nearly 5,000 Chevrolet Caprice PPV sedans.

The first action affects 392,459 full-size pickup trucks and SUVs that might inadvertently switch to neutral. This recall includes four-wheel-drive versions of the 2014-2015 model-year Chevrolet Silverado and GMC Sierra. Also included are the 2015-MY Chevrolet Tahoe and Suburban, along with the 2015-MY GMC Yukon and Yukon XL.

In these vehicles, the transfer case may electronically switch to neutral without the driver’s input. If this occurs when the vehicle is in motion, no power will go to the wheels. If the vehicle is stopped or parked without the parking brake set, the vehicle might unexpectedly roll away. Dealers will resolve the issue by recalibrating the transfer case control module software, GM said.

GM is also recalling 4,794 2013-2014 model-year Chevrolet Caprice police cars and 2014-MY Chevrolet SS sport sedans in the U.S. These vehicles may have faulty windshield wiper modules. If the motor gear teeth become stripped, the wipers may not operate, GM said. Dealers will make an inspection and replace the windshield wiper module assemblies if necessary.