52 15 057 Removing and installing / replacing valve housing for lumbar support / backrest width adjustment

Necessary preliminary tasks: 

• Remove Rear Panel On Front Seat 

Detach backrest cover (1) from backrest frame.

Fig 1: Identifying Backrest Cover

Courtesy of BMW OF NORTH AMERICA, INC.

Remove valve housing in direction of arrow from backrest frame.

1. Valve housing for backrest width adjustment.
2. Valve housing for lumbar support.

Installation: 

Check valve housing for correct seating in backrest frame.

Fig 2: Identifying Valve Housing For Backrest Width Adjustment And Lumbar Support

Courtesy of BMW OF NORTH AMERICA, INC.

Unfasten plug connection (1) and disconnect.

Unlock quick connector and detach air hoses (3) and (4 and 5) from valve housing (2).

Valve unit for lumbar support: 

1. (3) Hose (black), lumbar drive
2. (4) Hose (blue), top lumbar cushion
3. (5) Hose (red), bottom lumbar cushion

Valve unit for backrest width adjustment: 

1. (3) Hose (clear), lumbar drive
2. (4) Hose (clear), left lumbar cushion
3. (5) Hose (clear), right lumbar cushion
   NOTE: Connections are coded against incorrect assembly.
   Fig 3: Identifying Front Seat Plug Connection, Air Hoses And Valve Housing

   Courtesy of BMW OF NORTH AMERICA, INC.