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Power steering system unit (745)

Power steering system unit (745)

Location

Power steering system unit (745)

Main task

To supply servo oil to the power steering gear for generating power assistance to the car's steering system.

Type

The power steering system unit consists of a pump unit with oil reservoir, a control module and an electric motor. All are mounted as a complete unit on the steering gear.

Pump unit

Gear wheel pump that can generate max. 119 bar pressure. The pump is driven by a DC motor. The flow from the pump is regulated by the speed of the motor from 3l/min to max 6l/min. The length of the hydraulic hoses and the restrictors are tuned for quiet operation. An oil temperature sensor is connected to the EHPS control module. The temperature of the oil is measured continually.


Electric motor

Brushless DC motor powered directly and grounded by the integrated EHPS control module.


EHPS control module

The processor receives information from the P-bus, steering speed sensor, temperature sensor for power steering fluid and the circuit board. It calculates and ensures that steering force corresponds to vehicle speed and steering speed. It has a microprocessor - see Control module, general description . Cannot be programmed with SPS (Service Program System).


Connection

Pin
Signal type
Description
2 (K2) Power ground Power supply
1(K2) +30 Power supply
1(K5) +15 Power supply
2(K5) P-bus Signal to/from other control modules
3 (K5) P-bus Signal to/from other control modules