Investing.com -- The U.S. National Highway Traffic Safety Administration opened an investigation on Friday into 997,743 General Motors (NYSE: GM) pickup trucks and sport utility vehicles over engine failure concerns.

The probe covers vehicles including the Cadillac Escalade, Chevrolet Silverado 1500, and GMC Yukon from model years 2021 through 2026. All affected vehicles are equipped with GM's L87 engines.

The safety regulator received 499 complaints alleging engine failures in vehicles that had already received an earlier recall remedy.

GM issued a recall last year to address engine failure concerns in the affected L87 unit. The Detroit automaker said the issue was related to a supplier.

The NHTSA said its engineering analysis will examine post-recall engine failures and evaluate the effectiveness of GM's previous fixes.