Seat/Mirror Memory (SM/SPM)

Seat/Mirror Memory (SM/SPM):

Functional Description:

General Block Diagram:

Operation:

Set seat and mirror positions with the adjustment switches. Switch on ignition and press red "memory" button on the memory switch. Red LED lights, indicating the position can be stored (for a maximum of 10 sec). Press any selection button (1, 2 or 3), LED goes out after the seat and mirror positions have been stored.

The stored setting can be called as follows:

1. By briefly depressing the required button at:
- Ignition lock in R (position 1)
- Ignition lock in 0 and driver's door open

If any button is pressed once again, the setting procedure is terminated.

2. By pressing the required button until the position is reached at:
- Ignition lock in 0 and driver's door closed
- Ignition lock in 15 (position 2)

The setting procedure is stopped immediately when the button is released.

Operating Principle :

A set seat/mirror position is signaled to the control unit via a potentiometer (flange-mounted to each servo drive) in the form of a voltage where it can be stored if necessary. Voltage ranges: seat = 0.1 V to 4.5 V; mirror: 0 V to 4.5 V. When the stored position is called up, the currently applied voltage is compared in the control unit with the stored voltage. The control unit then implements adjustment with the aid of the servo drive until both voltage values are equal.

Relay Monitoring:

- For seat motor drives only -

All seat relays are switched off if one relay is held in the working position (relay sticking). The relay status is monitored every time the adjustment switch is operated. The relays are activated once again when the jammed relay is released.

Switching off the seat relays by the relay monitoring facility results in a closed-circuit current consumption of 1.4 A to 2 A (normal case: 10 sec after adjustment < 1 mA).

The BMW DIAGNOSTIC SYSTEM indicates whether the seat relays are OK. or defective.
Description of BMW DIAGNOSTIC SYSTEM