Electric Power Steering

In a previous blog article, I discussed how complicated products were becoming as a result of the rapidly changing technology industry.  In another example of complex technology, electric power steering is replacing hydraulic power steering.  For the most part, this isn’t news.  Two years ago however, GM began recalling 2010 Chevrolet Cobalt vehicles because the power steering motor would fail.  Keep in mind that in a hydraulic system, pressurized fluid would assist the driver in turning the front wheels either left or right.  In an electric system, the power steering motor does this job.  But, when it fails, power steering disappears.  When power steering disappears, more effort is required from the driver in order to maintain control of the vehicle.  If the driver is unprepared for the additional strength required, then the risk of a crash increases. This is also true for a hydraulic system.  It is understood that the power steering motor depends upon input from sensor(s) in order to determine the steering wheel’s position and whether to move the front wheels right or left.  GM has stated in their recall that the power assist will return the next time that the vehicle is restarted.  This statement implies that somehow, something in the motor has a tendency to fix itself and return to normal until the next time the “something” decides to cause the motor to fail.  It should be noted that although not proven, the power steering motor might have a tendency to alternately stop operating and then start again causing the steering wheel to oscillate back and forth. Doing so, will likely cause the vehicle to move sideways, back and forth.  We are investigating a situation with just this type of movement.  Just one more thing for the driving public to have to worry about. If you have experienced a power steering problem you are urged to have it checked.  The recall for this vehicle can be seen on the NHTSA website or on the GM website.