52 13 385 Replacing gas cartridge (pyroactivator) for crash-active head restraint on front seat

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WARNING: Read and comply with SAFETY REGULATIONS 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 .
Remove CRASH-ACTIVE HEAD RESTRAINT .

IMPORTANT: The pyrotechnical device may be replaced up to 5 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: Pyroactivator 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 pyroactivator.

Fig 1: Identifying Head Restraint

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Removing cover:

Raise cover (1) and pull towards rear.

Fig 2: Raising Cover

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Removing pyrotechnical device:

Press together retainer (1) for pyrotechnical device at lugs.

Feed out pyrotechnical device.

Fig 3: Pressing Retainer

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Removing pyroactivator:

Pull pyroactivator (2) out of mounting (1) for pyrotechnical device.

Unlock plug connection (3) and disconnect.

IMPORTANT: Dispose of plastic element and pyroactivator.

Fig 4: Identifying Pyroactivator, Mounting And Plug Connection

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Procedure for installing pyrotechnical device:

Bringing head restraint together - version without button (MFS):

Pull spring catches apart and push head restraint together.

Maintain position.

Fig 5: Pushing Head Restraint

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Bringing head restraint together - version with button (Basic):

Press button (1) and push head restraint together.

Maintain position.

Fig 6: Pushing Head Restraint

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Locking release plate:

Hold pushed-together head restraint in position and push release plate (1) upwards up to stop.

Release plate (1) must audibly snap into place.

Fig 7: Releasing Plate

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Checking head restraint lock:

Check end position of release plate (1).

All four springs must be engaged (snapped into place).

Fig 8: Locating Head Restraint Springs

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Replacing pyrotechnical device:

Connect plug (1) to new pyroactivator (2) and lock.

Clip pyroactivator (2) into new mounting (3).

Fig 9: Identifying Plug, Mounting And Pyroactivator

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Installing pyrotechnical device:

Press together retainer for pyrotechnical device at lugs.

Insert retainer for pyrotechnical device into release plate and tilt in upward direction.

Retainer for pyrotechnical device must audibly snap into place.

NOTE: Check seating of retaining lugs in retainer.

Fig 10: Installing Pyrotechnical Device

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Laying wiring harness:

Secure wiring harness in carrier section with strain relief.

Fig 11: Secure wiring harness in carrier section with strain relief

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Mounting cover:

Clip cover onto carrier section.

Cover must audibly snap into place.

Fig 12: Mounting Cover

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