BMW X3 Service & Repair Manual: Replacing wiring harness section for engine (N55)

IMPORTANT: Aluminum screws/bolts must be replaced each time they are released .

Aluminum screws/bolts are permitted with and without color coding (blue).

For reliable identification: Jointing torque and angle of rotation must be observed without fail (risk of damage) .

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

Necessary preliminary work:

• Read out the fault memory of the DME control unit.
• Switch off ignition.
• Disconnect BATTERY EARTH LEAD .
• Remove sound insulation at the rear of the engine.
• Remove intake PLENUM .
• Partially detach WIRING HARNESS for injectors and ignition coils.
• Remove CLEAN AIR PIPE .
• Remove FAN COWL .
• Remove front UNDERBODY PROTECTION .

Detach all connectors from Power Distribution Module (1). Release wiring harness from bulkhead.

Disconnect plug connection (2).

Release screws (3) and lay wiring harness to one side.

Release screws (1).

Unclip upper part of cable channel (2) and expose the wiring harnesses.

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

Installation note: Make sure grommets are correctly fitted (watertightness).

Release screws (1) below cable channel (2).

Replace aluminum screws.

Release screws (1).

Release cable channel (2).

Installation note:

Reconnect the earth connection.

Replace aluminum screws.

Release wiring harness if necessary from existing clips and clamps.

Feed out wiring harness and remove.

Installation note:

Check wiring harness installation arrangement.

Check plug connections for correct fit.

Check stored fault message.

Delete fault memory.