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

WARNING: This page is about a different car, the 2005 BMW 530i, 2005 BMW 525i, 2004 BMW 530i, and 2004 BMW 525i. However, it is still accessible from the selected car via links, so may be relevant.

WARNING: Scalding hazard!

Only perform these tasks on an engine that has cooled down.

Necessary preliminary tasks:

Read out fault memory of DME control unit.
Switch off ignition.
Disconnect battery negative lead from battery.
Follow instructions for Disconnecting And Connecting Battery .
E60 only: Remove microfilter housing lower sections on left and right. See CABIN AIR FILTER .
Remove engine cover.
Remove intake air manifold. See INTAKE MANIFOLD .
Remove underbody protection at front and rear.

NOTE: All illustrations show the E60/M54

Detach plug (1) from oil level sensor.

Unclip lead from cable tie (2) and lay towards top.

Fig 1: Detaching Plug From Oil Level Sensor

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Unlock plug (1) and detach from pulse generator for crankshaft (3).

Fig 2: Unlocking Plug And Detaching From Pulse Generator For Crankshaft

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Unscrew nuts (1).

Tightening torque, see 12 41 4AZ and 12 12 1AZ in ENGINE ELECTRICAL SYSTEM - TIGHTENING TORQUES .

Remove lines (2) from starter motor.

Fig 3: Removing Lines From Starter Motor

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

Fig 4: Unlocking Plug And Detaching From Coolant Temperature Sensor

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

Fig 5: Unlocking Plug And Detaching From Reverse Gear Switch

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

Fig 6: Uncliping Plug Connections On Oxygen Control Sensors

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Unfasten screws.

Remove electronics box cover (1).

Installation:

Engage electronics box cover (1) correctly in hinges.

Fig 7: Removing Electronics Box Cover

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Lift cables with profile seals (1) and (2) out of partition or electronics box.

Unlock plug connections in electronics box and disconnect.

Installation:

To prevent leaks, you must install profile seals (1) and (2) correctly.

Fig 8: Unlocking Plug Connections In Electronics Box

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Unlock plug (1) and detach from alternator.

Fig 9: Unlocking Plug And Detaching From Alternator

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Unlock plug connections (1) and (2) and disconnect.

Fig 10: Unlocking Plug Connections

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

Fig 11: Unlocking Plug On Pulse Generator Of Inlet Camshaft

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IMPORTANT: Mark plug connections (1) of oxygen monitor sensors for cylinder banks 1 of 3 and 4 of 6 to prevent them from being mixed up when they are installed later.

Unclip plug connections (1) from holders and disconnect.

Unlock and disconnect plug connection (3) on solenoid valve of VANOS adjustment unit.

Detach terminal strip (4) for fuel injectors from injection pipe.

Fig 12: Detaching Terminal Strip For Fuel Injectors From Injection Pipe

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

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

Fig 13: Unlocking Plug And Detaching Pulse Generator For Exhaust Camshaft

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Unlock plug (1) and detach from thermostat housing.

Fig 14: Unlocking Plug And Detaching From Thermostat Housing

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NOTE: Interrogate fault memory of DME control unit.

Check stored fault messages.

Rectify faults.

Then clear fault memory.