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:
