DETROIT >> Under pressure from U.S. safety regulators, Ford is recalling nearly 423,000 cars and SUVs in North America because the power-assisted steering can fail while they’re being driven.

The recall covers certain Ford Flex and Taurus vehicles, as well as the Lincoln MKS and MKT from the 2011 through 2013 model years. Also covered are the Ford Fusion and Lincoln MKZ from 2011 through 2012 and some 2011 Mercury Milans.

Ford says an intermittent electrical connection can cause the power steering to stop. That sends the steering into manual mode, making the vehicles harder to control. The company says it knows of four crashes due to the problem but no injuries.

Dealers will either update power steering control software or replace the steering gear depending on the problem with individual vehicles. A new steering gear eliminates the electrical issue.

In October, the National Highway Traffic Safety Administration began investigating complaints of power-steering failures on three Ford Motor Co. midsize car models. The probe covered 938,000 Ford Fusion and Lincoln MKZ cars from the 2010 through 2012 model years, as well as the 2010 and 2011 Mercury Milan.

According to a class-action lawsuit filed in June about the matter, the problem could affect more Ford models, including the compact Focus.

NHTSA said at the time that it received 508 complaints alleging that the cars lost power-assisted steering, causing increased steering effort.

Ford said it was unsure if the agency would close its investigation because of the recall. A message was left Wednesday for a NHTSA spokeswoman.

The company also is recalling 19,500 2015 Mustangs with 2.3-Liter engines due to high underbody temperatures that could degrade the fuel tank and fuel vapor lines, increasing the risk of a fire. No fires have been reported. The heat also can damage the parking brake cable. Dealers will replace a heat shield and add insulation.