General Motors (GM) is facing an engineering analysis by the US National Highway Traffic Safety Administration, or NHTSA, over reports of engine failures in pickup trucks and SUVs equipped with the company's L87 engines, NHTSA said Thursday.

The probe covers 997,743 vehicles from the 2021-2026 model years, including Chevrolet Silverado 1500, GMC Yukon and Cadillac Escalade models, among others, NHTSA said.

The agency said it received 499 complaints alleging engine failures after vehicles underwent an earlier recall remedy. NHTSA said it has also received 191 reports of L87 engine failures involving engines produced outside the manufacturing period covered by Recall 25V-274.

GM recalled the affected vehicles last year to address engine failure concerns and attributed them to a supplier manufacturing issue, according to the regulator.

NHTSA said the new engineering analysis will examine post-recall engine failures and assess whether GM's remedy was effective.