Seats: Description and Operation

Seat Mirror Memory (SM/SPM):

Functional Description:

Set seat and mirror positions are signaled as a voltage value via a potentiometer (mounted on the relevant actuator) to the control unit and if the driver requires - these positions can be stored. Voltage ranges covered by the potentiometers:

- Seat motor drive: 0.1 V to 4.5 V
- Mirror motor drive: 0 V to 4.5 V

When the Driver calls up a stored position, the control unit compares the voltage currently applied to the stored voltage. Adjustment takes place by way of the drive motors (actuator) until the voltage values agree.

Operation:

A required seat or mirror position is set by way of the adjustment switches (on the driver's seat). The system is ready to store values after switching on the ignition and pressing the "memory". The current seat/mirror position is stored by pressing the store buttons "1, "2" or "3".

Stored positions are called up by:

Pressing the required button until the position is reached.

The adjustment procedure stops immediately as soon as the button is released.

Relay Monitoring (only Seat Motor Drives):

All seat relays are switched off if one relay sticks in the operating position (relay freeze). The status of the relays is monitored every time the adjustment switch is operated. Deactivation of the relays is canceled when the relevant relay no longer sticks.

Deactivation of the relays by way of the relay monitoring function results in a closed-circuit current consumption of approx. 1.4 A to 2.0 A (normally 10 s after adjustment <1 mA).

Defective seat relays can be detected by way of the diagnostic program (defect code memory).

System components/control Unit Location:

The SM/SPM control unit is located under the driver's seat. The control unit drives 4 (5 for sport seat) seat and mirror adjustment motors. Attention: No head-restraint adjustment motors in integral seat version.

Seat motors: One motor each for seat tilt, seat movement, seat height, backrest adjustment and, if sport seat is installed, adjustment of the thigh support.

Mirror motors: Two motors each (driver/passenger side) for left/right adjustment.