Bosch is recalling nearly 558,000 electric power steering systems with aluminum mounting bolts that can corrode and break, allowing the steering gears to detach and causing the vehicles to lose power steering.
Bosch says the aluminum bolts are especially susceptible to corrosion in states where road salt is routinely used in the winter months.
The aluminum mounting bolts attach the electric motors to the housings of the electric power steering systems. Bosch says it decided to order the recall based on recalls from two automakers.
In April 2015, Ford issued a recall of 2013-2015 Ford Fusion, Lincoln MKZ and 2015 Ford Edge vehicles due to the aluminum bolts. Ford vehicles in areas where road salt was used had the power steering mounting bolts replaced, while vehicles in other areas received extended warranties to cover future repairs.
Three years later in March 2018, Tesla recalled 123,000 Model S cars after reports of corroded power steering bolts in states where road salt is used.
The parts supplier says it hasn't found a defect in the bolts, and the power steering systems were tested and validated to the specifications set by automakers. According to Bosch, it hasn't noticed increased warranty claims in other manufacturers' vehicles and isn't aware of any crashes or injuries related to the power steering.
A driver will lose power steering but manual steering will remain because the steering gear motor won't detach from the vehicle, leading Bosch to say there is no unreasonable risk to safety.
However, a driver who loses power steering while traveling at slow speeds or turning around corners may need to use a lot more effort to keep the vehicle on the road.
Bosch says a driver may notice symptoms that include noise when turning the wheel, in some cases a warning light may activate and finally limited power steering assist.
Many drivers who formally knew nothing about a company called Bosch have become aware of the name the past few years due to the Volkswagen emissions scandal.
In addition, parts supplied by Bosch have also been named in class-action lawsuits filed by owners of Chrysler and General Motors vehicles.