FEDERAL safety regulators have received over the last four years about 150 complaints with a common theme from owners of the 2012 Ford Focus: The power steering can turn off, leaving the driver with a harrowing encounter as the car becomes difficult to maneuver.

In addition, regulators have received 124 reports from Ford Motor of injuries or deaths attributed to what was broadly termed a steering problem. One crash was fatal, Ford reported.

Regulators have not opened a formal investigation into the issue, and Ford has not taken any action beyond twice alerting dealers to potential problems with the power steering.

For the drivers involved, the loss of power steering could be terrifying.

“I was driving in the Interstate going about 65 miles per hour with my child in the car,” a mother from Indiana wrote to the National Highway Traffic Safety Administration in October. “My power steering went out. A semi was right next to me, and I almost went off trying to keep from hitting it.”