12 51 210 Replacing wiring harness section for ignition and injectors (N20, N26)

IMPORTANT: Read and comply with notes on PROTECTION AGAINST ELECTROSTATIC DISCHARGE (ESD PROTECTION) .

Necessary preliminary work:

Read out the fault memory of the DME control unit.
Switch off ignition.
Remove acoustic cover . See 11 12 090 REMOVING AND INSTALLING/RENEWING ACOUSTIC COVER (N20) or 11 12 090 REMOVING AND INSTALLING/RENEWING ACOUSTIC COVER (N26)
N20 only:
Remove PRESSURE CONVERTER FOR EXHAUST TURBOCHARGER .

Fig 1: Overview Of Ignition And Injectors Wiring Harness Section
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Overview of wiring harness section for ignition and injectors.

Unlock and remove connector (1) from control unit.

Fig 2: Identifying Control Unit Connector

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Release wiring harness from clamps (1).

Fig 3: Identifying Wiring Harness Clamps

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NOTE: This procedure is applicable to all cylinders.

Unlock and disconnect connector (1) at injectors.

Slacken nut (1) and remove ground cable (3).

Tightening torque 12 52 2AZ .

Fig 4: Identifying Ground Cable, Connector And Nut

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NOTE: This procedure is applicable to all cylinders.

Release connector catch (1) at ignition coil (2) and pull off connector.

Fig 5: Releasing Connector Catch At Ignition Coil

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Unlock retaining lug (1) in direction of arrow.

Pull cable channel (2) from cylinder head cover.

Pull out and remove wiring harness section for injectors and ignition coils.

Fig 6: Releasing Retaining Lug

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NOTE: Check stored fault messages.
Clear diagnostic fault entries from fault memory.