Replacing Backrest Frame
721955 Replacing Backrest Frame
Preliminary work
1. Remove cushion carrier.
NOTE: Only for vehicles with lumbar support.
2. Remove control valve for lumbar support adjustment.
NOTE: Only for vehicles with lumbar support.
3. Remove lumbar support.
NOTE: Only for vehicles with lumbar support.
4. Remove motor for lumbar support.
NOTE: Only for vehicles with adaptive sports seats.
5. Remove air cushion for backrest.
Disassembling backrest frame
Removing foam part
1. Remove foam part -1- at the headrest.
Removing supports for backrest side parts
1. Unscrew fastening screws -1- and remove support for right backrest side part -2-.
2. Unscrew fastening screws -1- and remove support for left backrest side part -2-.
Removing inner spring on backrest frame
1. Disengage tension springs -1- at left and right on inner spring -2- (-arrows A-).
2. Unclip inner spring -2- on backrest frame at the drive shaft -arrow B- and remove inner spring.
3. Disengage tension springs -1- on the backrest frame.
Disconnecting wire harnesses on backrest frame
NOTE:
- Only for vehicles with lumbar support.
- Make sure not to trap or damage the wire harness when pulling it through.
1. Pull wire harness for backrest -1- down out of the backrest frame -2-.
2. Turn plug connection -1- approx. 90° anti-clockwise -arrow A- and pull it off the backrest frame -arrow B-.
3. Release plug connection -arrows C- and disconnect it -arrows D-.
NOTE: Make sure not to trap or damage the wire harness when pulling it through.
4. Press locking tabs on fixing clip -2- together and unclip it -arrow E-. Pull wire harness for backrest -3- down and out -arrow F-.
5. Press locking tabs on fixing clip -2- together and unclip wire harness for side airbag -4- from the backrest frame -arrow G-.
Removing frame for side airbag
1. Unscrew fastening screws -1- and unclip frame for side airbag -2- from the backrest frame -3-.
Disassembling backrest frame
1. Remove fastening nuts -1- from the backrest frame -2-, check them and replace if necessary.
2. Unclip fixing clips -1- from the backrest frame -2-, check them and replace if necessary.
Removing backrest frame
NOTE: Two persons are needed to remove and install the backrest frame.
1. Secure backrest frame -2- in upright position.
2. Unscrew fastening screws -1- on left and right and remove backrest frame -2- up out of the seat frame.
Assembling backrest frame
Installing backrest frame
DANGER:
Loosen the safety screws.
- Danger of injury if front seat is not screwed down correctly.
- Always replace fastening screws for the front seat after customer service and reworking.
- It is not permissible to make alterations to the micro-encapsulated screws (e.g., use lubricant, loosen bolts, and screw them down again).
NOTE: Two persons are needed to remove and install the backrest frame.
1. Fit backrest frame -2- into the seat frame, position it correctly and secure with the fastening screws -1-.
Tightening torque: 34 Nm (25 ftlb.) ± 4 Nm (± 3 ftlb.)
Assembling backrest frame
1. Press in fixing clips -1- on the backrest frame -2-.
2. Screw fastening nuts -1- onto the backrest frame -2-.
Installing frame for side airbag
1. Clip frame for side airbag -2- to backrest frame -3- and secure with the fastening screws -1-.
Securing wire harnesses on backrest frame
NOTE:
- Only for vehicles with lumbar support.
- Make sure not to trap or damage the wire harness when pulling it through.
1. Pull wire harness for backrest -1- up into the backrest frame -2-.
2. Press fixing clip -2- on wire harness for side airbag onto the backrest frame -arrow A-.
NOTE: Make sure not to trap or damage the wire harness when pulling it through.
3. Pull wire harness for backrest -3- through -arrow B- and press in fixing clip -2- (-arrow C-).
4. Push plug connection -1- together -arrows D- until it engages securely.
5. Insert plug connection -1- into the backrest frame -arrow E- and turn it clockwise by approx. 90° -arrow F-.
Installing inner spring on backrest frame
1. Engage tension springs -1- in the backrest frame.
2. Clip in inner spring -2- on lower part of backrest frame at the drive shaft -arrow A-.
3. Engage tension springs -1- in the inner spring -2- on the backrest frame -arrow B-.
Installing supports for backrest side parts
NOTE:
- Observe hose routing.
- In vehicles with lumbar support, make sure the hoses are routed correctly in the area of the backrest side support.
1. Insert support for left backrest side part -2- and secure with the fastening screws -1-.
2. Route wire harness for side airbag -1- as shown behind the backrest side part support -2-.
NOTE:
- Observe hose routing.
- In vehicles with lumbar support, make sure the hoses are routed correctly in the area of the backrest side support.
3. Insert support for right backrest side part -2- and secure with the fastening screws -1-.
Fitting foam part
1. Fit foam part -1- to the headrest.
Subsequent work
NOTE: Only for vehicles with adaptive sports seats.
1. Install air cushion for backrest.
NOTE: Only for vehicles with lumbar support.
2. Install motor for lumbar support.
NOTE: Only for vehicles with lumbar support.
3. Install lumbar support.
NOTE: Only for vehicles with lumbar support.
4. Install control valve for lumbar support adjustment.
5. Install cushion carrier.