12 51 306 Removing and installing/replacing supply module wiring harness section (N63 B40/44 O 1)

WARNING: This page does not describe the selected car, but rather 33 other vehicles, including the 2018 BMW M6, 2018 BMW 650i xDrive, 2018 BMW 650i, 2018 BMW 640i xDrive, and 2018 BMW 640i. However, it is still accessible from the selected car via links, so may be relevant.

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

IMPORTANT: Screw back on all screw points of cable channels without fail! Some screw points are also ground points. If the wiring harnesses are not correctly screwed tight and secured, this may cause DME malfunction and failure!

Necessary preliminary tasks:

Read out the fault memory of the DME control unit.
Switch off ignition.
Disconnect NEGATIVE BATTERY CABLE .
Remove right suspension cross-brace. See 51 71 346 REMOVING AND INSTALLING/REPLACING RIGHT (REAR) SUSPENSION CROSS-BRACE .
Remove sound insulation for bulkhead on right. See 51 71... REMOVING AND INSTALLING/REPLACING SOUND INSULATION FOR BULKHEAD UPPER PART .
Remove left trailing link. See 51 71... REMOVING AND INSTALLING/REPLACING (FRONT) LEFT OR RIGHT SUSPENSION CROSS-BRACE .
Remove right-hand. See INTAKE SILENCER HOUSING .
Remove intake port on left and right. See 13...... REMOVE THE INTAKE PORT (N63 B40/B44 O 1) .
Remove underbody protection at front and rear. See 51 47 490 REMOVING AND INSTALLING/REPLACING FRONT UNDERBODY PROTECTION and 51 47 491 REMOVING REFITTING/REPLACING REAR ENGINE UNDERCOVER .
Only F12 and all-wheel drive vehicles:
Remove stiffening plate. See 31 11 039 REMOVING AND INSTALLING/REPLACING FRONT STIFFENING PLATE (ALL-WHEEL DRIVE VEHICLE) and 31 11 040 REMOVE AND INSTALL/REPLACE STIFFENING PLATE (ALL-WHEEL DRIVE) .

Fig 1: Overview Of Supply Module Wiring Harness
Courtesy of BMW OF NORTH AMERICA, INC.

Overview of supply module wiring harness section.

Picture shows the left side, the procedure for the right side is identical. Slacken nut (1).

Tightening torque 12 51 2AZ .

Remove ground cable.

IMPORTANT: If the nut (1) is released, the ground pin (double pin) underneath must be retightened!
Retighten ground pin.
Tightening torque 12 51 3AZ .

Fig 2: Identifying Slacken Nut

Courtesy of BMW OF NORTH AMERICA, INC.

Release screws (1).

Release clamp (2).

Remove lid (3) from auxiliary box.

Fig 3: Identifying Clamp, Screws And Lid

Courtesy of BMW OF NORTH AMERICA, INC.

Disconnect all plugs from carrier plate (1) and release from supplementary electronics box.

Installation note:

Make sure rubber grommets are correctly fitted (water tightness).

Fig 4: Identifying Plugs From Carrier Plate

Courtesy of BMW OF NORTH AMERICA, INC.

Release screw (1).

Tightening torque 17 22 4AZ .

Release screw (2).

Tightening torque 17 22 5AZ .

Remove engine oil pipes from oil filter control housing and take off oil sump. Catch and dispose of emerging oil.

Installation note:

Replace all sealing rings of engine oil pipes!

Fig 5: Identifying Screw Of Engine Oil Pipes

Courtesy of BMW OF NORTH AMERICA, INC.

Check the engine oil level after repair work is completed. Top up, if applicable.

Unlock and disconnect following connectors and lines
Unlock connector on transmission and disconnect
Unlock connector of DME control units and pull off
Unlock plug connection to wiring harness section sensor system module cylinder 1-4 (in vicinity of starter motor) and pull off.

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.

Clear diagnostic fault entries from fault memory.