194003106 - E7045 ELECTRIC STEERING - DESCRIPTION (ESP)

The EHPS (Electrical Hydraulic Power Steering) is a power assisted steering device designed to reduce the effort required for steering the vehicle by using the torque from an electric motor.The power assisted steering is the electrohydraulic type and its intervention varies according to the speed of the vehicle and the steering angle.The power assisted steering is programmed so that its effects decrease as the speed of the vehicle increases. In this way it is possible to turn the steering wheel with great ease whilst parking and maintain safe contact with the road whilst driving at high speed.In practice, the system varies the hydraulic assistance (pump rpm) according to the rotation speed of the steering and the speed of the vehicle thereby being able to produce greater assistance when parking and extremely low hydraulic assistance at speed.An electronic control unit, an integral part of the CAN, manages and controls the system: processing the input information and using the internal operating logic, the control unit determines the direction of rotation and the supply current for the electric motor producing the desired servo-assistance effect.The system is available in two versions:- on all versions where ESP is not fitted as standard, the steering angle signal is supplied by a sensor connected directly to the steering column;- on all versions where ESP is fitted as standard, the steering angle system is supplied, via the CAN, by the steering angle node located on the vehicle steering wheel.The control unit is equipped with an autodiagnostic function: when an error is detected in the Electric Steering function, the electric steering failure warning light in the instrument panel is lit up.The presence of serious errors in the function activates an emergency (recovery) condition.For more details,See descriptions 4110 STEERING CONTROL AND LINKAGEThe battery power supply line for the control unit is protected by a specific maxifuse in the battery control unit; the ignition-controlled power supply (INT from the steering lock control unit) is protected by a fuse in the junction unit under the dashboard.