12 51 100 Replacing wiring harness section for ignition coils (M54)

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.

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.

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.

Fig 1: Detaching Plug Of Wiring Harness For Ignition Coils From DME Control Unit

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

Unlock plug (1) and detach from ignition coils.

Unlock cable strip (2) and remove towards top.

Fig 2: Unlocking Cable Strip And Remove Towards Top

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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.

Fig 3: Removing Cable Together With Profile Seal

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Installation:

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

E39 only:

Release locks (1).

Fig 4: Releasing Locks

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

Installation:

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

Z3, E46, E53 and E39:

NOTE: Interrogate fault memory of DME control unit. Check stored fault messages. Rectify faults. Then clear fault memory.