Design

Design

Power Steering Control Module (PSCM)




1. Control module with power stages.
2. Pump motor.
3. Pump.
4. Connection for power supply (30-supply) and ground terminal.
5. Connection for 15-supply and CAN.
Power Steering Control Module (PSCM) consists of a module, where the following main components are included:
- control module
- a pump motor
- pump.
The Power Steering Control Module (PSCM) is located under the right-hand headlamp. The Power Steering Control Module (PSCM) can only be replaced as one unit. The control module, pump motor and pump cannot be replaced as separate components.

Control module
The control module is built into the pump motor casing. All the electrical terminals are on the top of the control module. The control module has logic control for all functions which enables it to read, write and store software and diagnostic trouble codes (DTCs). The control module also manages all communication with the other control modules via the controller area network (CAN).
The control module contains a number of power stages, field effect transistors (FET). The field effect transistors control the output of the pump motor upon request from the control module. The control module also has a built-in NTC temperature sensor (low temperature results in high resistance, high temperature in low resistance). This allows the control module to diagnose, limit or disengage the power steering if an excessive temperature is registered or there are other faults in the control module.

Hydraulic pump (pump/pump motor)
The hydraulic pump consists of a pump and a pump motor. The pump is in an oil reservoir. The pump motor, which drives the pump, is under the reservoir. The pump motor is a brushless DC motor. The pump motor also has Hall sensors. The Hall sensors provide the control module with information about the speed of the pump motor, and therefore the prevailing hydraulic pressure (which is indirectly speed dependent). This allows the control module to control and diagnose the pump motor.