Electrically Operated

Unit, Power Steering Unit (745)

Main task
To supply the power-assisted steering gear with power steering fluid in order to generate power assistance to the car's steering system.

ALLDATA Editor Note:
The EHPS system appears to be only offered with the 1.8L Z18XE motor that is controlled by the Simtec control module (705) instead of the 2.0L Trionic control module (589), but is included here both for reference and as a safeguard for vehicle variance.

Type
The power steering unit consists of a pump unit with oil container, control module and an electric motor. Everything is fitted as one complete unit on the steering gear.

Pump unit
Gear pump which can provide max.119 bar pressure, the pump is driven by a DC motor. The flow from the pump is regulated with the speed of the motor, regulating occurs from 3 l/min to max.6 l/min.The length of the hydraulic hoses and restrictions are tuned to provide quiet operation. A temperature sensor measuring oil temperature is connected to the EHPS control module. The temperature of the oil is measured continuously.







Electric motor
Brushless DC motor with direct current supply and grounding from the integrated EHPS control module.







EHPS control module
The processor receives information from the P-bus, the steering speed sensor, the temperature sensor for power steering fluid and the circuit board, and it calculates and ensures that the steering force is in proportion to the vehicle speed and steering speed inputs. It has a microprocessor. It is not programmable with SPS (Service Program System).







Connection