12 51 245 Removing and installing the wiring harness section for the engine and transmission module (B48)

Necessary preliminary tasks: 

• Disconnect the BATTERY NEGATIVE LEAD .
• Remove the CORROSION PROTECTION COVER .
• Remove the FRONT UNDERBODY PROTECTION .
• Remove the REAR UNDERBODY PROTECTION .
• Remove the TRANSMISSION CROSS MEMBER FOR TRANSMISSION MOUNT.
• Partially remove PROPELLER SHAFT .

Removal: 

Overview of the wiring harness section for the supply transmission module. 

Loosen the clamps along the arrows.

Unlock and disconnect plugs (1).

Unfasten screws (2).

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Unlock and disconnect following connectors and lines	Note
Unlock and loosen the connector from DME control unit
Unlock and loosen the connector from power distribution box
Unlock and loosen the connector on the air conditioning compressor
Loosen terminal 50 on starter motor
Unlock and loosen the connector on the automatic transmission.

Remove cover (1).

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Unlock and loosen the wiring harness section connector (1) for supply transmission module.

Unlock and loosen the wiring harness section connector (2) for supply transmission module.

Unlock and loosen the wiring harness section connector (4) for supply transmission module.

Release wiring harness section for the supply transmission module from the holder (3) and lay to one side.

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Unlock and detach connector (1) along the direction of the arrow.

Unlock and disconnect plugs (2).

Unlock and disconnect plugs (3).

Unlock holder (4) and release.

Unlock holder (5) and release.

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Release circlips (1).

Unlock locks (2) in direction of arrow.

Feed out fuel hose (3) and remove.

Catch and dispose of escaping fuel.

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Release wiring harness from clips and retainers.

Feed out wiring harness and remove.

Installation: 

Overview of the wiring harness section for the engine supply transmission module. 

Attach clamps along the arrows.

Tighten the screws (2) of the ground cable on the cylinder head.

Tightening torque, refer to: 12 52 6AZ .

Tighten the screw (2) of the cable channel on the cylinder head.

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Tightening torque, refer to: 12 52 4AZ .

Attach and lock connector (1).

Connector (1) must engage audibly.

Connect and lock the following connectors and lines	Note
Connect and lock the connector of DME control unit
Connect and lock the connector on power distribution box
Connect and lock the connector to the automatic transmission.
Connect and lock the connector on air conditioning compressor
Tighten terminal 50 on starter motor	Tightening torque, refer to: 12 42 3AZ .

Thread in and install the fuel hose (3).

Locks (2) must engage audibly.

Fasten circlips (1).

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Attach and lock connector (1) in direction of arrow.

Connect connector (2) and lock.

Connect and lock connector (3).

All connectors must audibly engage.

Fasten holder (4).

Fasten holder (5).

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Connect and lock the wiring harness section connector (1) for supply transmission module.

Connect and lock the wiring harness section connector (2) for supply transmission module.

Connect and lock the wiring harness section connector (4) for supply transmission module.

All connectors must audibly engage.

Fasten wiring harness section for the supply transmission module on the holder (3).

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Install cover (1).

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Route and install wiring harness.

Plug in all connectors as specified in table.

All connectors must audibly engage.

Required follow-up work: 

• Install the PROPELLER SHAFT .

• Install the TRANSMISSION CROSS MEMBER FOR THE TRANSMISSION BEARING.
• Install the CORROSION PROTECTION COVER .
• Install the FRONT UNDERBODY PROTECTION .
• Install the REAR UNDERBODY PROTECTION .
• Connect the BATTERY EARTH LEAD .