12 63 520 Replacing main relay (S62, M54)

WARNING: This page is about a different car, the 2003 BMW 525i, 2002 BMW 525i, 2001 BMW 525i, and 2000 BMW 528i. However, it is still accessible from the selected car via links, so may be relevant.

Switch off ignition.

Release retaining clips (1).

CAUTION: The air duct can brake at the firewall if not carefully removed and installed.

Carefully twist air duct (2) upwards until it is no longer locked in firewall. Pull air duct (2) forwards and lift out.

Fig 1: Releasing Retaining Clips

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Open locking bracket (1). Open cover on microfilter housing (2) and unhook from hinges.

Open retaining clip (3).

Pull microfilter housing to right and lift out.

Installation:

Hook cover of filter housing into hinges in correct position.

Incorrect installation leads to sealing problems.

Fig 2: Removing Microfilter Housing

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Release screws (1).

Tightening torque. Refer to ENGINE ELECTRICAL SYSTEM - TIGHTENING TORQUE .

Remove cover (2) from electronics box.

Fig 3: Removing Electronics Box Cover

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Arrangement:

Main relay of Digital Motor Electronics
Engine fuses for Digital Motor Electronics

Fig 4: Identifying Digital Motor Electronics Main Relay & Engine Fuses
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Notes on troubleshooting:

If the starter turns during the engine starting sequence but the engine fails to start:

Check engine fuses
If fuses are blown, replace them completely with fuse holder
Find out why fuses have blown