The variable assist magnetic steering system (Magna Steer)
varies the driver effort required to steer the vehicle as speed changes. At
low speeds, the system requires minimum steering effort for easy turning
and parking maneuvers. Steering effort is increased at higher speeds
in order to provide the driver with firmer steering (road feel) and
directional stability. The EBCM controls a bi-directional magnetic rotary
solenoid. The solenoid is located in the steering gear. The EBCM
varies the steering assist by adjusting the current flow through
the solenoid. The solenoid adjusts the amount of power steering
assist in order to achieve a given level of driver effort to
turn the vehicle.
Magna Steer accomplishes this by adding or subtracting torque on the
rotary input shaft to the power rack and pinion. The amount of steering
assist is dependent upon vehicle speed. As the vehicle speed increases,
the following actions occur:
| • | The steering assist decreases. |
| • | The driver effort increases. |
As the vehicle speed decreases, the following actions occur:
| • | The steering assist increases. |
| • | The driver effort decreases. |
The scan tool can be used to adjust the amount of steering assist if
the customer requests. The steering assist has 3 settings:
