12 51 100 Replacing wiring harness section for ignition coils (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.

Interrogate fault memory of DME control unit. Switch off ignition.

Follow instructions for disconnecting and connecting battery. Refer to 12 00... Instructions for disconnecting and connecting battery .

Disconnect battery negative lead from battery.

E53 only:

Remove heater bulkhead.

Z3, E39, E46, E53:

Remove cover for ignition coils.

Detach plug of wiring harness for ignition coils from DME control unit. Disconnect plug connection of wiring harness for ignition coils in electronics box.

NOTE: Do not remove DME control unit.

Detach grounding strap (2) of cable duct from connecting plate of ignition coils between cylinders 2 and 3.

Fig 1: Detaching Cable Duct Grounding Strap

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Unlock plug (1) and detach from ignition coils.

Unlock cable strip (2) and remove towards top.

Fig 2: Removing Cable Strip

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E53 only:

Remove water reservoir for windshield washer system. See 61 71 061 REPLACING FLUID TANK FOR WINDSHIELD WASHER SYSTEM

Remove cable (1) with profile seal from partition wall (3).

Unclip cable (2) from partition wall (3).

Release screw connection of partition wall (3) with body.

Remove partition wall (3).

Fig 3: Removing Cable With Profile Seal From Partition Wall

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Pull profile seal (1) out of electronics box.

Release locks (2).

Remove strip (3).

Pull out profile seal (4).

Installation:

To prevent leaks, you must install profile seals (1 and 4) correctly.

Fig 4: Removing Profile Seal From Electronics Box

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E46 and Z3 only:

NOTE: Shown on the E46. The same procedure applies to the Z3.

Pull off sealing strip (1).

Remove cable (3) together with profile seal (2) from partition wall towards top.

Installation:

To prevent leaks, you must install profile seal (2) correctly.

Fig 5: Removing Cable With Profile Seal From Partition Wall (E 46 & Z3)

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E39 only:

Release locks (1).

Remove cable (3) together with profile seal (2) from partition wall towards top.

Installation:

To prevent leaks, you must install profile seal (2) correctly.

Fig 6: Removing Cable With Profile Seal From Partition Wall (E 39)

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Z3, E46, E53 and E39:

NOTE: Interrogate fault memory of DME control unit.

Check stored fault messages.

Rectify faults.

Then clear fault memory.