Lumbar Support Adjustment, Basic Function - GF91.00-S-9902A

Model All (Light transporter) 

Example illustration of lumbar support adjustment 

Courtesy of MERCEDES-BENZ USA

Overview 

This document contains information on:

• General information 
• Function requirements 
• Function 

General information 

To achieve optimum support of the vertebral column, the backrests on the driver and front passenger seat are each equipped with a lumbar support unit. This adjusts the shape of the seat backrest padding with the aid of two air cushions in the backrest.

Function requirements 

• Circuit 15R ON or run-on active
• No overvoltage or undervoltage
• No on-board electrical system limp-home mode

Function 

Adjustment is performed using the lumbar support adjustment switch (4) of the respective seat. The lumbar support adjustment control unit (2) of the respective seat reads in the status of the lumbar support adjustment switch (4). It then actuates the corresponding inflation or deflation of the air cushions through the valves integrated into the lumbar support adjustment control unit (2). For the compressed-air supply system, the lumbar support adjustment control unit (2) actuates the lumbar support pneumatic pump (3).

After switching off circuit 15R, adjustment of the lumbar support is still possible for another 180 s (run-on time). If, during the run-on time, the circuits status or the door status is changed, the run-on time starts again.