Speed sensitive power steering

Fig 1: Speed Sensitive Power Steering Communication Diagram

Courtesy of VOLVO CARS OF NORTH AMERICA.

The central electronic module (CEM) (4/56) receives information that the engine is running from the engine control module (ECM) (4/46) on the controller area network (CAN). It receives information about vehicle speed from the brake control module (BCM) (4/16). The central electronic module (CEM) then controls the power steering control module which in turn acts on the solenoid.

The central electronic module (CEM) checks the signals. If a fault is detected, the servo assistance is set to normal (approximately 70 km/h) and the system is disengaged. The central electronic module (CEM) also transmits a signal to the driver information module (DIM) (5/1) via the control area network (CAN) which lights the general warning lamp and displays a text message.