12 51 100 Replacing wiring harness section for ignition and injectors (N63)

IMPORTANT: Read and comply with notes on protection against damage from electrostatic discharge (ESD protection). Refer to NOTES ON PROTECTION AGAINST ELECTROSTATIC DAMAGE .

IMPORTANT: Screw back on all screw points of cable channels without fail! Some screw points are also ground points . If the wiring harnesses are not correctly screwed tight and secured, this may cause DME malfunction and failure!

Necessary preliminary work:

Read out the fault memory of the DME control unit.
Switch off ignition.
Disconnect BATTERY NEGATIVE LEAD .
Remove left and right INTAKE SILENCER HOUSINGS .
Remove INTAKE PIPES on left and right
Partially release WIRING HARNESS for engine.

Release screws (1).

Tightening torque 12 90 2AZ .

Remove electronics box cover (2).

Fig 1: Identifying Electronics Box Cover And Screws

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Unlock all connectors (1) from control unit and disconnect.

Unclip grommet hold-down device (2) and remove.

Detach rubber grommets (3) from electronics box. Place wiring harnesses to the side.

Installation note:

Make sure grommets are correctly fitted (watertightness).

Fig 2: Identifying Rubber Grommets, Grommet Hold-Down Device And Connectors

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Release clamps (1) and (2).

Replace clamps (2).

Detach both charge-air ducts (3) and remove.

Check the gaskets on the exhaust turbocharger. replacing if necessary.

Fig 3: Identifying Charge-Air Ducts And Clamps

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Picture shows the left side, the procedure for the right side is identical.

Detach hoses (1) from clean air pipe.

Release screw (2).

Tightening torque 13 71 1AZ .

Detach clean-air pipe (3) in direction of travel from exhaust turbocharger.

Check the gasket on the clean air pipe. replacing if necessary.

Fig 4: Identifying Clean-Air Pipe, Hoses And Screw

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Release screws (1).

Tightening torque 12 51 2AZ .

Unlock plugs on injectors and ignition coils and detach.

Release wiring harness (2).

Release wiring loom (3) and lay to one side.

IMPORTANT: Screw back on all screw points of cable channels without fail. Some screw points are also ground points.

Fig 5: Identifying Wiring Harness, Loom And Screws

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Release screw (1).

Tightening torque 12 51 2AZ .

Raise cable duct (2).

Fig 6: Identifying Cable Duct And Screw

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Pull off cable duct (1) from cable clip (2) in upward direction.

Cable (3) does not have to be released.

Fig 7: Pulling Off Cable Duct From Cable Holder

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Release screws (1).

Tightening torque 12 51 2AZ .

Raise cable duct (2).

Fig 8: Identifying Cable Duct And Screws

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Release screws (1).

Tightening torque 12 51 2AZ .

Release screw (2).

Unlock plugs on injectors and ignition coils and detach.

Lay wiring harness (3) to one side.

Feed out air wiring harness (4) and remove.

IMPORTANT: Screw back on all screw points of cable channels without fail. Some screw points are also ground points .

Fig 9: Identifying Wiring Harness, Loom And Screws

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NOTE: Check wiring harness installation arrangement.
Check plug connections for correct fit.
Check stored fault message.
Clear diagnostic fault entries from fault memory.