12 51 200 Replacing wiring harness section for injectors (N57 D30 O T 1)

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

Necessary preliminary tasks:

Switch off ignition.
Read out the fault memory of the DDE control unit.
Disconnect BATTERY EARTH LEAD .
Remove ACOUSTIC COVER
Remove ACOUSTIC COVER at rear and remove sound insulation on injectors.
Remove MICROFILTER HOUSING .

Lever out expanding rivet.

Remove gasket (1).

Unfasten screws (2).

Feed out partition wall (3) and remove.

Fig 1: Identifying Partition Wall, Gasket And Screws

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Lever out expanding rivet.

Release locks in direction of arrow.

Feed out fresh-air duct (1) and remove.

Fig 2: Releasing Fresh Air Duct Locks

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Open retainers.

Release lock (1) in direction of arrow.

Remove cover (2).

Fig 3: Removing Cover

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Release screws and remove retaining bracket (1).

Unclip rubber grommets on downholder.

Unlock upper section (2) of partition seal in direction of arrow and remove.

Release grommets (3) for wiring harnesses from lower section of partition seal and from electronics box.

Installation note:

Make sure grommets are correctly seated (watertightness).

Fig 4: Unlocking Upper Section Of Partition Seal

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Disconnect all plugs (1) from control unit.

Release wiring harness for injectors from electronics box.

Fig 5: Identifying Control Unit Plugs

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Graphic of injector wiring harness (Note: Graphic shows right-hand drive vehicle; for left-hand drive vehicles, the electronics box is on the right):

Fig 6: Overview Of Injector Wiring Harness

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Unlock all connectors on injectors and disconnect.

Undo screws on wiring harness if necessary.

Feed out wiring harness for injectors under pressure lines and engine wiring harness and remove.

Installation note:

To ensure watertightness, make sure the wiring harness rubber grommet for injectors is correctly inserted.

NOTE: Check wiring harness installation arrangement.
Check plug connections for correct fit.
Reassemble the vehicle.
Read out the fault memory of the DDE control unit.
Check and rectify stored fault messages.
Clear diagnostic fault entries from fault memory.