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

WARNING: This page is about a different car, the 2003 BMW X5, 2002 BMW X5, and 2001 BMW X5. 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 And E46:

Remove reinforcement plate.

CAUTION: The article FRONT AXLE SUPPORT contains important installation instructions.

Remove underbody protection.

E53, E46, E39:

Detach plug (1) from oil level sensor.

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

Fig 1: Detaching Plug From Oil Level Sensor

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When fitted:

Remove vacuum tank for exhaust flap.

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

Fig 2: Unlocking Plug Connection From Pulse Generator

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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: Detaching Leads From Starter Motor

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

Release cable tie (2).

Fig 4: Detaching Plug Connection From Coolant Temperature Sensor

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Disconnect plug connection (1).

E53 Only:

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

Fig 5: Releasing Cable Tie On Transmission Housing And Disconnecting Cable

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

Fig 6: Detaching Plug Connection From Reverse Gear Switch

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E53 And E46 Only:

Remove heater bulkhead. Refer to 51 71 080 REMOVING AND INSTALLING/REPLACING HEATER BULKHEAD .

E53, E46 And E39:

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

Fig 7: Unclipping 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 12 14 550 REPLACING CONTROL UNIT (DIGITAL MOTOR ELECTRONICS) (M62, M54) .

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: Detaching Profile Seal

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Detach profile seals (1) towards top.

Installation:

To prevent leaks, you must install profile seals correctly.

Fig 10: Detaching Profile Seals Towards Top

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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 11: Detaching Plug Connector From Alternator

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

Fig 12: Detaching 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 13: Detaching Plug From Solenoid Valve Of VANOS Adjustment Unit

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Unlock plug (1) and detach from thermostat housing.

Fig 14: Detaching Plug 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.