Government Investigates 938,000 Ford Sedans for Steering Problem

After the Ford Motor Company recalled about 1.1 million vehicles this year for power steering failures, the National Highway Traffic Safety Administration is investigating the same problem on another 938,000 cars.

The safety agency is investigating whether a recall is necessary on Ford Fusion and Lincoln MKZ sedans from the 2010-12 model years and Mercury Milan sedans from the 2010 and 2011 model years, according to a report posted Monday on the agency’s website.

N.H.T.S.A. says it has received 508 complaints from owners, including four reports of accidents that occurred when the power steering assist suddenly failed, requiring “increased steering efforts that contributed to a loss of control and crash.” No injuries were noted. The complaints go back to 2010 and include many reports of close calls.

“As the vehicle was attempted to be turned right into driveway the power steering completely failed and the driver nearly hit another vehicle,” one owner wrote the safety agency in August 2013. “Every bit of the 120-pound female driver’s strength was needed to manually steer the vehicle into the parking lot.”

The owner also said that the repair cost $1,600.

Last year, Ford recalled nearly 1.2 million vehicles in the United States. So far this year, Ford has recalled about 3.9 million vehicles. That includes two recalls in May for sudden power steering assist failures. The largest action, which covered about 915,000 Ford Escape and Mercury Mariner crossovers from the 2008-11 model years, was prompted by an investigation by Transport Canada, Canada’s counterpart of the N.H.T.S.A.

The Canadian agency’s investigation began in 2011, based on owner complaints, but Ford resisted a recall, saying the vehicles could still be steered. Transport Canada continued to push, leading to the recall. About 736,000 of the affected vehicles were in the United States. There is no indication on the N.H.T.S.A. website that the American agency ever opened an investigation into that problem.

Ford also recalled about 195,500 Explorer S.U.V.s from the 2011-13 model years in May for loss of power steering assist. That included about 178,000 vehicles in the United States.

Ford is cooperating with N.H.T.S.A. in the new investigation, Kelli Felker, a spokeswoman for Ford, wrote in an email. The investigation is called a preliminary evaluation. If the agency finds additional reason for concern it will upgrade the investigation into an engineering analysis. An engineering analysis is more likely — but not certain — to lead to a recall.

In other actions:

■ Nearly 25,000 Ram ProMaster vans from the 2014 model year are being recalled because the head restraint may not properly protect front seat occupants in a rear-impact crash, according to a report Chrysler filed with N.H.T.S.A. It is the fourth recall of the vans this year.

■ About 1,600 SRT Viper sports cars from the 2013-14 model years are being recalled by Chrysler Group because the driver’s side air bag may not deploy properly, according to a report posted on the safety agency’s website. The automaker said a sensor designed to detect how close the driver’s seat is to the air bag was not working properly, and in a crash the air bag might deploy with less force than needed to protect the driver.

The automaker described the recalls as voluntary but once a manufacturer is aware of a safety problem it must — within five business days — inform the safety agency of its plan for a recall or face a civil fine.