12 42 540 Replacing safety battery terminal (SBK)

WARNING: This page does not describe the selected car, but rather 15 other vehicles, including the 2005 BMW 325xi, 2005 BMW 325i, 2005 BMW 325Ci, 2004 BMW 325xi, and 2004 BMW 325i. However, it is still accessible from the selected car via links, so may be relevant.

CAUTION: Observe safety regulations. Investigate cause of triggering of safety battery terminal.

To do so, read out fault memory of airbag control unit. Note fault messages stored in memory.

Rectify faults. Then clear fault memory.

Use of safety battery terminal:

From model year 1998 in Series E38, E39, E46.
From 4/99 in E36/Z3.
In each of following new Series.

The different models have different installation locations:

Battery In Engine Compartment

Safety battery terminal is replaced with cable up to battery positive support point.

Safety Battery Terminal Is Omitted As From 03/2002 From All E46 LHD Models With 4-Cylinder Engines .

Battery In Luggage Compartment Behind Side Trim Panel

Remove side trim panel.

Follow instructions for disconnecting and connecting battery, refer to 12 00... INSTRUCTIONS FOR DISCONNECTING AND CONNECTING BATTERY .

Disconnect and cover battery negative lead.

Fig 1: Disconnecting And Cover Battery Negative Lead

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Release front side trim panel partly and fold forward.

Fig 2: Releasing Front Side Trim Panel Partly And Fold Forward

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Battery In Luggage Compartment Under Floor Trim Panel

Follow instructions for disconnecting and connecting battery, refer to 12 00... INSTRUCTIONS FOR DISCONNECTING AND CONNECTING BATTERY .

Fold back floor trim panel (1).

Lift cover (2) on battery negative lead.

Disconnect and cover battery negative lead (3).

Release nuts (4).

Remove battery cover.

Fig 3: Folding Back Floor Trim Panel

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Battery In Luggage Compartment Under Spare Wheel

Remove spare wheel.

Release screws.

CAUTION: Do not kink air pipes.

Set air supply system (1) to one side.

Fig 4: Setting Air Supply System To One Side

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Follow instructions for disconnecting and connecting battery, refer to 12 00... INSTRUCTIONS FOR DISCONNECTING AND CONNECTING BATTERY .

Disconnect battery negative lead.

Disconnect supply cable (1) for vehicle electrical system.

Fig 5: Disconnecting Supply Cable For Vehicle Electrical System

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Installation:

Remove faulty fuses and carry out troubleshooting.

CAUTION: Pay attention to interface. The repair cable is always a standard length. The heavy-current connector of the repair cable has a larger diameter than the battery positive lead. In some Series (e.g. E46 touring), the heavy-current connector of the repair cable can lead to installation problems. This is the case when the interface is in the area of the close-fitting trim panels. Find matching interface (e.g. approx. 10 cm behind rear seat backrest in E46 touring).

Lay repair cable parallel to battery positive lead.

Mark interface of battery positive lead at end of repair cable.

Fig 6: Identifying Mark Interface Of Battery Positive Lead At End Of Repair Cable

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Release cable ties (1).

Disconnect plug connection (2).

Fig 7: Releasing Cable Ties

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CAUTION: Do not use bolt cutters or similar tools to cut through the cable. A cable end that has been squashed flat will no longer fit into the clamping sleeve.

Saw through battery positive cable at marked point with an iron saw.

Fig 8: Identifying Cable