GF91.29-P-0004GMA Electric Seat Adjustment (ESA) Function

GF91.29-P-0004GMA Electric Seat Adjustment (ESA) Function
- except CODE (275) Memory package (driver seat, steering column, mirrors)
- except CODE (242) Electrically adjustable front passenger seat with memory

Function requirements, general
^ Circuit 15R ON or
^ Run-on active

Electric seat adjustment function description, general
The seat adjustment is described at the driver seat for left-hand drive vehicles as an example; the same is valid for the front passenger seat.

The electric seat adjustment (ESA [ESV]) allows the electrical adjustment of the driver and front passenger seat.
Adjusting possibilities:
- Seat height
- Backrest angle
- Seat inclination
- Seat lengthwise adjustment

The scope of code (845) 3rd seat row folding down electrically, is described in the function description of the electric seat adjustment (ESA [ESV]) function with code (275) Memory package (driver seat, steering column, mirror) and code (242) Electrically adjustable front passenger seat with memory.

Run-on:
If circuit 15R was switched off, the ESA [ESV] can only be operated for t = 180 s. If a change in the circuit status or in the door status occurs during the run-on time, the run-on function begins anew. The rear SAM control unit (N10/8) receives the circuit status from the EIS [EZS] control unit (N73) via the interior CAN (CAN B).

A tumbler contact is installed in each door lock. The door status (open or closed) is read in by the rear SAM control unit via a direct line, which then switches a relay in the load compartment fuse and relay box (F4) and thus starts the run-on function for the electric seat adjustment.

Abort conditions
- Overvoltage or undervoltage

The ESA [ESV] enables the following subfunctions:
^ Manual seat adjustment
^ Anti-lock device

Manual adjustment
The corresponding switch must be actuated and held for the seat adjustment:
- Driver seat adjustment switch (S22)

When this occurs, the corresponding seat adjustment motor is actuated directly by the corresponding switch:
- Driver seat fore/aft adjustment motor (M27/1),
- Driver rear seat height adjustment motor (M27/2),
- Driver front seat height adjustment motor (M27/3),
- Driver backrest angle adjustment motor (M27/5).

The seat adjustment motors are supplied with power by the rear SAM control unit via the load compartment fuse and relay box directly via the respective seat adjustment switch.

Anti-lock device
Since the ESA [ESV] does not have a sensor system or its own control unit, the antilock device is actuated by means of a thermal fuse in the seat adjustment motors. As a result, if the seat adjustment motor is blocked, it is not switched off until exceeds a certain temperature threshold.