The National Highway Traffic Safety Administration says it will investigate problems with stalling or surging engines in nearly 725,000 Ford cars and SUVs.
The probe affects Ford Escape and Mercury Mariner SUVs and Ford Fusion and Mercury Milan sedans from the 2009 through 2011 model years.
The vehicles can unexpectedly go into “limp mode” at reduced power, the agency said in documents posted Monday on its website. NHTSA and Ford have received almost 1,500 complaints about the problem. There were three crashes and one injury.
NHTSA began looking into the cars and SUVs after getting a request from the North Carolina Consumers Council last year. Nonprofit safety groups and consumers can petition the agency to investigate vehicle problems.
The cars and SUVs haven’t been recalled, but the investigation could lead to a recall.
The North Carolina organization said it received two complaints about 2009 Escapes that had been diagnosed with throttles either stuck open or closed. The group said that owners reported repeated stalling and surging.
Ford said Monday that it’s cooperating with NHTSA on the investigation.
The Dearborn, Mich., automaker has been hit by a series of safety recalls on new versions of the Fusion and Escape, two of its most important products. Ford says it has fixed those problems, and it expects U.S. market share to go up this year as new products go on sale.