12 51 100 Replacing wiring harness section for ignition coil (N52K / N51)

WARNING: This page does not describe the selected car, but rather 14 other vehicles, including the 2013 BMW 328xi, 2013 BMW 328i, 2012 BMW 328xi, 2012 BMW 328i, and 2011 BMW 328xi. However, it is still accessible from the selected car via links, so may be relevant.

IMPORTANT: Aluminium-magnesium materials.

No steel screws/bolts may be used due to the threat of electrochemical corrosion.

A magnesium crankcase requires aluminium screws/bolts exclusively.

Aluminium screws/bolts must be replaced each time they are released .

The end faces of aluminium screws/bolts are painted blue for the purposes of reliable identification.

Jointing torque and angle of rotation must be observed without fail (risk of damage) .

IMPORTANT: Read and comply with Notes On Protection Against Electrostatic Damage (ESD Protection).

Necessary preliminary tasks:

Read out fault memory of DME control unit
Switch off ignition
Disconnect Battery Negative Lead
Remove Ignition Coil Cover
Remove Intake Duct

Unlock fasteners (1) from below and slide upwards approx. 10 mm.

Unlock locks (2) in direction of arrow.

Remove cover (3).

Fig 1: Identifying Fasteners, Locks, Cover And Removal Direction

Courtesy of BMW OF NORTH AMERICA, INC.

Unlock plug (1) and remove.

Unlock control unit (2) and raise approx. 5 cm.

Release grommet (3) from electronics box.

Installation:

Make sure grommet (3) is correctly seated in electronics box (watertightness).

Fig 2: Identifying Plug, Control Unit And Grommet

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Unlock tab (1), pull contact carrier (2) in direction of arrow out of housing.

Unlock and disconnect all plug connections of ignition coil wiring harness section in electronics box.

Fig 3: Identifying Contact Carrier, Tab And Removal Direction

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Press locking tabs (1) in direction of arrow and pull contact carrier (2) out of housing.

Fig 4: Identifying Locking Tabs, Contact Carrier And Removal Direction

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Press locking tab (1) in direction of arrow and pull contact carrier (2) out of housing.

Fig 5: Identifying Locking Tabs, Contact Carrier And Removal Direction

Courtesy of BMW OF NORTH AMERICA, INC.

WORK STEP CHART

Work step	Note:
Disconnect positive lead at jump-start connection point
Disconnect ground cables
Unlock plug connections on ignition coils and disconnect
Unlock cable duct on cylinder head cover and detach
Unlock plug on eccentric shaft sensor and disconnect
Unlock plug on positioning motor for eccentric shaft and disconnect
Unlock plug on both solenoid valves and disconnect
Unlock plug on inlet and exhaust camshaft sensors and disconnect
Unlock plug on A/C compressor and disconnect
Unlock plug on oil pressure switch and disconnect
Unlock plug on coolant temperature sensor and disconnect
Disconnect connector strip from fuel rail
Remove front Underbody Protection
Unlock plug on electric coolant pump and disconnect
Unlock plug on coolant thermostat and disconnect
Disconnect engine ground connection	For tightening torque refer to 3AZ in 12 52 PLUG CONNECTIONS, TERMINALS, LOOSE PARTS . Replace screw.

NOTE: Check stored fault messages.

Now clear the fault memory.