Electrically operated driver's seat with memory function: Function
The seat can be adjusted when the ignition is ON and when the conditions for COMFORT FUNCTION are met. Comfort enable is primarily controlled by the key position. Information comes on the instrument bus from the CIM (Column Integration Module).
The DSM (Driver Seat Module) is supplied with +30 from fuse 25 in the rear electrical center REC.
The driver seat module DSM reads the status on the switch in question in the switch unit and activates if necessary the driver's seat motors.
4D
Convertible
A number of DC motors (4D: four, Convertible: five, four as from 560007970) move the seat lengthways, change the seat cushion height and tilt and change the backrest rake. Each motor has an integral Hall sensor, the control module uses the information from these sensors to calculate the seat position.
The switch unit consists of a number of switches which are fed with B+ from the control module. When the switch makes, the B+ voltage is fed back to the corresponding switch input on the control module. The voltage is then changed from 0V to B+.
When a valid section of switch is detected, the control module performs a corresponding function, i.e. voltage feeds the motors with manual adjustment. The polarity of the motors is reversed to change the direction of rotation.
When the motors run, the control module monitors each motor's power consumption and counts pulses from the Hall sensors and can thereby calculated the position when setting from memory.