System Description

System Description

The seat memory is installed in the vehicle as optional equipment in connection with electrically adjustable seats and rearview mirrors.

The advantage in comparison with the base version is that there are three memory locations to store the set positions. The stored positions can then be called up at the push of a button. If the vehicle is used by several persons, the seat and mirror positions must only be set once and stored in the system.

System readiness
The system allows the position to be changed if at least one of the following requirements is fulfilled.
- Term. 15 is switched on or
- The driver's door is opened

Operational readiness is maintained for an after-running time of 60 s after the key has been removed or the door has been closed. If the position is changed during the after-running time, then the after-running time is started again. If the position is not changed during the after-running time, then the system switches to inactive state, thus reducing power consumption.

NOTE: Term. 15 must be switched on for communication with the PST 2.

System components
The system consists of the following components:
- Lumbar support
- Motor for lumbar support (lumbar pump)
- Switch for seat adjustment
- Electric motor for seat adjustment
- Electric motor for front height adjustment
- Electric motor for rear height adjustment
- Electric motor for backrest adjustment
- Control module for memory seat adjustment
- Switch for memory seat adjustment
- Switch for rearview mirrors (door mirrors)
- Changeover switch for rearview mirrors (door mirrors)
- Right and left rearview mirrors (door mirrors)

The system enables the following system components to be adjusted individually.
- Front seat height
- Rear seat height
- Backrest angle
- Left rearview mirror
- Right rearview mirror
- Lumbar support
- Fore-and-aft adjustment

Storing the positions
1. Adjust the rearview mirrors, seat height, backrest angle and lumbar support to the desired positions.
2. Hold down switch M and push one of the switches for memory seat adjustment (1, 2 or 3) at the same time.

The positions are now stored under the number selected.

Diagnosis
The following components are monitored by the system:
- Lumbar pressure sensor (regulating switch)
- Potentiometer voltage of both rearview mirrors
- Hall-effect sensor for backrest adjustment
- Hall-effect sensor for fore-and-aft adjustment
- Hall-effect sensor for height adjustment
- Functioning of the control module (EPROM, A/D converter, main relay)
- Switch for memory seat adjustment and switch for seat adjustment

When the switch for memory seat adjustment or the switch for seat adjustment are actuated, the faulty component is stored in the fault memory. In this case the word present also appears on the screen, e.g.

"Open circuit present in Hall-effect sensor for fore-and-aft adjustment"

If the cause of the fault is eliminated, then the switch for memory seat adjustment or the switch for seat adjustment must be actuated again. If the cause of the fault has really been eliminated, the text in the fault memory changes from present to not present.

NOTE: The fault memory must always be read out and any faults which may have been stored must always be deleted after diagnosis.