Replacing Gas Cartridge (Firing Unit) for Crash-Active Head Restraint on Front Seat

52 14 385 - Replacing gas cartridge (firing unit) for crash-active head restraint on front seat





Warning!
Read and comply with safety regulations [1][2][3]72 .. ... Safety Precautions and General Information for handling airbag modules and pyrotechnical belt pretensioners.
Incorrect handling may result in triggering of the crash-active head restraint and thereby cause injury.

Switch off ignition!






Necessary preliminary tasks:
- Disconnect battery negative lead 61 20 900 Disconnecting and Connecting Battery Negative Lead





Important!
The firing unit may be replaced up to 4 times.
Triggering frequency is denoted on the sticker on the head restraint carrier.
Stickers are available as spare parts.





Starting situation:
Head restraint is in the crash position after being triggered.

Note:
Firing unit can only be removed in the triggered state.
The complete crash-active head restraint must be replaced if the event of a head restraint fault signal and an untriggered firer.





Lever out cover welt in marked area.
Remove cover with padding from head restraint.





Unclip service flap.
Move firing unit (1) forwards and remove towards front.





Unfasten plug connection (1) and disconnect.
Replace firing unit.

Installation Note:
Plug connection (1) must audibly snap into place.
Check firm engagement of plug connection (1) by gently pulling on plug.
Lay cable in side guide.





Press locking spring (1) on left and right through opening and secure with dowel pins (or similar).
Head restraint is unlocked.






Important!
This work requires a great exertion of effort!

Pull head restraint (1) at an angle downwards until it is completely in lowest position and rests on linkage.
Hold head restraint (1) in this position for the following tasks.





Clip firing unit (1) onto linkage (2).

Installation Note:
Check that firing unit (1) is firmly seated on linkage.

Press firing unit (1) forwards and clip into place.

Important!
Firing unit (1) must audibly snap into place.





Installation Note:
Visually check that firing unit is correctly seated.
Attach sticker for identification after replacement.
Clip service flap into place.