For 1990-2009 cars

The variable effort steering (VES) system uses inputs from the ABS wheel speed sensors and steering wheel speed sensor to the EBCM to determine the desired amount of power steering assist.

The power steering pump actuator has a pintle that moves in and out of an orifice, regulating power steering fluid flow. The EBCM can change the amount of current flowing through the actuator. If the actuator is disconnected, the pintle will retract out of the orifice for maximum power steering assist.

The EBCM has the ability to detect malfunctions in the steering wheel speed sensor, the actuator or the circuitry to those components. Any malfunction detected will cause the power steering assist to remain at maximum with the pintle in its normally retracted position for all speeds.

When the system is operating normally, increasing the vehicle speed will decrease power steering assist, allowing the driver to have improved road feel and directional stability. When the EBCM steering wheel speed sensor detects sudden steering maneuvers, the EBCM reduces the actuator current in order to provide maximum steering assist.