12 51 001 Replacing wiring harness section for engine (M54)

WARNING: This page is about a different car, the 2003 BMW 530i, 2002 BMW 530i, and 2001 BMW 530i. 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.

WARNING: Scalding hazard!
Only perform these tasks on an engine that has cooled down.

E53, E46, E39:

Detach plug (1) from oil level sensor.

Unclip cable from cable holder (2) and lay upwards.

Fig 1: Disconnecting Oil Level Sensor Cable Clip

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When Fitted:

Remove vacuum tank for exhaust flap.

Unlock plug (1) and detach from pulse generator for crankshaft.

Fig 2: Disconnecting Crankshaft Pulse Generator Plug Lock

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Release nuts (1).

Tightening torque, refer to 12 41 4AZ in ENGINE ELECTRICAL SYSTEM - TIGHTENING TORQUES .

Detach leads (2) from starter motor.

Fig 3: Removing Starter Motor Leads

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Unlock plug (1) and detach from coolant temperature sensor.

Release cable tie (2).

Fig 4: Disconnecting Coolant Temperature Sensor Cable Tie

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Disconnect plug connection (1).

E53 only:

Release cable tie (2) on transmission housing and disconnect cable (3).

Fig 5: Disconnecting Wiring Harness Cable Tie & Plug Connection

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Unlock plug (1) and detach from reverse gear switch.

Fig 6: Unlocking Reverse Gear Switch Plug

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E53 and E46 only:

Remove heater bulkhead.

E53, E46 and E39:

Unclip plug connections (1) on oxygen control sensors from holders and disconnect.

Fig 7: Uncliping Plug Connections On Oxygen Control Sensors

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E53 only:

Disconnect all plugs in control unit box.

One part of this operation is described in the section "Replacing control unit".

Unlock cable holders (2).

Remove cables (1) from cable holders (2).

Release screws (3).

Remove holder (4).

Fig 8: Removing Cables From Cable Holders

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Release nut.

Remove grounding cables from ground support point.

Detach profile seal (1) towards top.

Installation:

To prevent leaks, you must install profile seals correctly.

Fig 9: Identifying Profile Seal

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Detach profile seals (1) towards top.

Installation:

To prevent leaks, you must install profile seals correctly.

Fig 10: Removing Wiring Harness Along With Profile Seals

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E46 only:

Pull off sealing strip (1).

Fig 11: Removing Sealing Strip

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Withdraw vacuum line and battery positive lead from assembly compartment partition wall.

Turn fasteners (1) through 90 °. This unlocks the fasteners (1).

Remove assembly compartment partition wall (2) towards top.

Fig 12: Removing Assembly Compartment Partition Wall Along With Vacuum Lines

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Installation:

To ensure watertightness, it is essential to install profile seals of vacuum line, battery positive lead and engine wiring harness correctly.

Release screws (1).

Installation:

Tightening torque, refer to 12 90 4AZ in ENGINE ELECTRICAL SYSTEM - TIGHTENING TORQUES .

Remove cover from electronics box.

Fig 13: Removing Electronics Box Cover

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Pull out profile seal (1).

Unlock plug (2) and disconnect.

Fig 14: Disconnecting E-Box Connectors

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E39 only:

Disconnect all plugs in control unit box.

One part of this operation is described in 12 14 550 REPLACING CONTROL UNIT (DME) (M52, M62, M54) .

Remove air duct on left and right, refer to 64 31... REMOVING AND INSTALLING/REPLACING AIR DUCT FOR MICROFILTER ON LEFT OR RIGHT .

Release fasteners (1).

Detach rubber strip (2).

Fig 15: Removing Firewall Panel Strip Fasteners

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Release fasteners (1).

Remove firewall panel (2).

Fig 16: Removing Firewall Panel

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E53, E46 and E39:

Remove throttle assembly, refer to 13 54 030 REMOVING AND INSTALLING/SEALING THROTTLE ASSEMBLY (M54) .

Remove intake air manifold, refer to 11 61 050 REMOVING AND INSTALLING INTAKE AIR MANIFOLD (M54) .

Unlock plug (1) and detach from alternator.

Fig 17: Unlocking Alternator Plug

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Unlock plug (1) on pulse generator of inlet camshaft and detach from cable duct (2).

Fig 18: Unlocking Plug On Pulse Generator Of Inlet Camshaft

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Unlock plug (1) and detach from solenoid valve of VANOS adjustment unit.

Unlock plug (2) and detach from pulse generator for exhaust camshaft.

Fig 19: Disconnecting VANOS Adjustment Unit & Exhaust Camshaft Pulse Generator Connectors

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Unlock plug (1) and detach from thermostat housing.

Fig 20: Disconnecting Thermostat Housing Connector

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