2014 BMW 740Li Power Steering Control Module Replacement Cost

Power steering systems have developed over the past couple of decades, and are now responsible for assisting the driver with turning power and increasing subtlety at high speeds. To accomplish the first task, assisting with physically turning the wheels, mechanical components are sufficient. But, to assist with adding subtlety to steering at high speeds, an electronic means of control must be added. To control that system, the electronic power steering control module is used.

Electronic power steering is accomplished by placing a motor on the steering column or steering gear, and controlling the operation of that motor with, you guessed it, a control module. That control module will sense the position of the steering wheel, note which direction the steering wheel is turning, and how fast is is being turned. Also, the control module senses the speed of the vehicle, angle of headlights, and many other factors relating to driver control of the vehicle. It will then determine how much force to apply to the steering gear, what ratio it should turn the wheels at, and when to change those variables. This not only allows the driver to subtly or dramatically alter the path of the vehicle, but it allows the steering wheel to remain completely separate from the wheels.

Power steering control modules can fail causing a number of symptoms, including, but not limited to, power steering and other warning light illumination, steering wheel becoming stiff or nearly impossible to turn, speed sensitivity is no longer accurate, turning radius may seem to increase or decrease, an excessive number of turns of the steering wheel may be necessary to turn the vehicle. These result because the control module determines the ratio at which to turn the wheels. In other words, the steering control module will decide if turning the steering wheel a complete revolution will turn the wheels ten degrees or thirty degrees. It should be noted that erratic operation of the steering system or loss of steering ability is not common, but is possible.