The probe, announced Tuesday by the National Highway Traffic Safety Administration, affects 730,000 SUVs from the 2001 to 2004 model years that are powered by V-6 engines.
The safety agency said it has received 99 complaints from owners of the SUVs alleging 13 crashes, nine injuries and one death caused by the problem. The throttles on the SUVs can fail to return to idle when the driver takes his foot off the gas pedal, according to agency documents.
Sixty-eight of the complaints were about the Escape, and 31 involved the Tribute, a nearly identical vehicle made by Ford for Mazda. Dearborn, Mich-based Ford used to own about one-third of Mazda. But Ford began cutting ties in 2008, and in 2010 lowered its ownership to 3.5 per cent.
Investigators are looking into whether the sticky throttles could have been caused by repairs made as part of a 2004 recall of the same vehicles. About 590,000 of the vehicles were recalled in December of 2004 to fix an accelerator cable defect, and the documents say the repairs could have damaged the cruise control cable.
The investigation is among the larger probes started by NHTSA in 2012. While many affect fewer than 100,000 vehicles, the agency this year began looking into door fires affecting 1.4 million Toyota Camry midsize sedans and RAV4 small SUVs. It also expanded a fuel tank fire probe in older-model Jeep Grand Cherokee SUVs to include 5.1 million vehicles.
NHTSA investigations are the first step toward a recall, but they don't always cause cars and trucks to go back to dealerships for repairs.
The SUV investigation comes just over a week after the Center for Auto Safety, a Washington, D.C., advocacy group petitioned NHTSA to investigate the Escape and Tribute problems. The group also wants a hearing on whether Ford and Mazda met obligations to notify owners and fix defects in their vehicles.
But NHTSA said in documents filed Tuesday that it has denied the group's petition because the agency has been looking at the Escape and Tribute problems since early in 2012. The agency said it began gathering information after the driver of a 2002 Escape was killed in a crash in Payson, Ariz., this past January.