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System Overview: Signals

The table below summarizes the input signals to and output signals from the Power Steering Control Module (PSCM). The signal types are divided into directly connected signals and CAN communication. The illustration below displays the same information with the Volvo component designations.

Input signals Output signals
Directly connected:  Directly connected: 
Ignition  (3/1):
  • Position II (15-supply) activates the Power Steering Control Module (PSCM).
Via CAN communication:  Via CAN communication: 
Steering wheel angle sensor module (SAS)  (4/68):
  • This information is used together with the vehicle speed signal from the brake control module (BCM) to calculate the desired value for the pump motor speed.

Brake control module (BCM)  (4/16):
  • Actual vehicle speed (calculated from the wheel speed sensors). Used for the speed related steering assistance.

Engine control module (ECM)  (4/46)
  • Indicates whether the engine is running or not (engine status/engine speed).

Central electronic module (CEM)  (4/56):
  • Information about vehicle configuration and power mode.
Driver information module (DIM)  (5/1):
  • For certain registered faults the Power Steering Control Module (PSCM) transmits a request via the central electronic module (CEM) (4/56) to light or extinguish the information lamp and display a text message in the driver information module (DIM) (5/1).
Fig 1: Power Steering Control Module (PSCM) Signal Types
GLL171043Courtesy of VOLVO CARS CORPORATION