BMW 7 Series: Repairing Airbag Cables

IMPORTANT: Only repair those cables which show visible signs of damage. In the event of visible damage, make sure there is only one cable repair in effect after the repair work. If no visible damage can be identified, the entire cable must be replaced. When carrying out repairs to the airbag wiring harness, you must use the spare parts offered in the Electronic Parts Catalogue (EPC).

Safety regulations

Safety regulations for HANDLING COMPONENTS OF AIRBAG SYSTEM.

INSTRUCTIONS FOR DISCONNECTING AND CONNECTING BATTERY.

Procedure for cable repair

In event of non-visible damage to wiring harness

Disconnect plug connection on airbag module or on adapter plug. It is absolutely vital to disconnect the contacts in succession as there is a risk of them being mixed up! Cut through one cable after the other at an appropriate wiring harness with insulating tape. Now disconnect plug connection on airbag control unit. Unpin contacts. Cut through one cable after the other at an appropriate position and insulate with insulating tape, do not under any circumstances cut through both cables at the same time. Pin contacts of repair cable for airbag control unit in control unit plug, assignment of repair cables is relevant. Lay repair cable in car parallel to existing airbag lead.

Now pin in contacts for airbag control unit or contacts of adapter plug, assignment of repair cables is relevant.

Cut off excess length of repair cable in proximity (visible area) of airbag module or of adapter plug. Twist open cables. With the connectors and shrink-fit hoses in the Electronic Parts Catalogue (EPC), reconnect the cables with the same cable colors. Twist cables again, open length (twist) must not exceed 40 mm. Secure interface (shrink-fit hoses) with insulating tape to prevent cables from twisting open.

Instructions for cutting off, insulating, crimping cables, installing and removing contacts:

• CUTTING OFF AND INSULATING CABLES
• REPAIRING A PLUG CONNECTION USING CONNECTORS
• INSTALLING AND REMOVING CONTACTS

In event of visible damage

Expose cable at damaged areas. Cut through one cable after the other at an appropriate position and insulate cables no longer required in wiring harness with insulating tape, do not under any circumstances cut through both cables at the same time. Now, depending on the scope of work, unpin contacts either on airbag control unit/airbag module or on adapter plug. Cut off unpinned cables. Insulate cables remaining in wiring harness with insulating tape. Now pin in contacts of repair cable, assignment of repair cables is relevant. Lay repair lead in car parallel to existing airbag lead up to cutting point. Cut off excess length of repair lead. Twist open cables.

Connect cables with connectors and shrink-fit hoses in Electronic Parts Catalogue (EPC), assignment of repair cables is relevant. Twist cables again, open length (twist) must not exceed 40 mm. Secure interface (shrink-fit hoses) with insulating tape to prevent cables from twisting open.

Instructions for cutting off, insulating, crimping cables, installing and removing contacts:

• CUTTING OFF AND INSULATING CABLES
• REPAIRING A PLUG CONNECTION USING CONNECTORS
• INSTALLING AND REMOVING CONTACTS

SAFETY INFORMATION FOR WORKING ON VEHICLES WITH AUTOMATIC ENGINE START-STOP FUNCTION (MSA)

WARNING: If the engine hood/bonnet contact is pulled upwards (workshop mode), the information "switch closed" is output. The automatic engine start-stop function is active.

An automatic engine start is possible.

Observe safety precautions when working on MSA vehicles

Before carrying out practical work on the engine, always ensure that the MSA functionality is deactivated so as to prevent automatic engine starting while work is being carried out in the engine compartment.

MSA function is deactivated by

• Deactivate MSA by means of button (1) in passenger compartment
• Open seat belt buckle and driver's door

Fig. 4: Identifying MSA Button

• Open engine bonnet/hood and ensure that engine hood/bonnet contact is not in workshop mode
  • Workshop mode
    A = 10 mm
  • Basic setting (engine hood/bonnet open)
    B = 7 mm

To make sure that the engine hood/bonnet contact is at the basic setting, if necessary press the hood/bonnet contact up to the limit position before starting work and slowly release.

Fig. 5: Identifying Basic Setting For Engine Hood/Bonnet Open

When working with diagnosis tools

• Observe instructions in diagnosis tool

TREATING CABLES AND FIBRE-OPTIC CABLES

Notes

NOTE: Special tools referred to in the repair instructions below are contained in the following special tool kits:

SPECIAL TOOLS DESCRIPTION CHART

Subject of repair instructions

• SPECIAL TOOLS FOR WIRING HARNESS REPAIRS
• CUTTING CABLES TO LENGTH AND STRIP INSULATION
• Crimping stop parts (contacts)
• BUTT CONNECTOR FOR REPAIRING A PLUG CONNECTION
• COMB CONNECTOR FOR RETROFITTING/REPAIRS
• Cutting to length and stripping insulation from optical fibres and crimping optical fibres

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