12 14 555 Replace the control unit (DME) for cylinders 1-4 (N63 B40/B44 O 1)

IMPORTANT: READ and comply with notes on protection against electrostatic damage (ESD protection)

Recycling

Catch and dispose of drained coolant.

Observe country-specific waste disposal regulations.

Necessary preliminary tasks:

IMPORTANT: Follow INSTRUCTIONS for removing and installing control units

Replacement:

Carry out programming/encoding
If no data can be read out from the previous control unit, carry out injection quantity compensation (description at end of instructions).

IMPORTANT: It is absolutely essential to read out the fault memory with the BMW diagnosis system and to create a fault memory printout.

Switch off ignition.

Unlock all plugs (1) from control unit and detach.

Unclip wiring harnesses from cable clips.

Fig 1: Identifying Plugs From Control Unit

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Release clamps (1), detach coolant hoses. from the control unit and close.

Release the coolant hose from clamp (2).

Unscrew nuts (3).

Remove control unit.

NOTE: Catch and dispose of escaping coolant.

Fig 2: Identifying Coolant Hose Clamps And Nuts

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Injection quantity compensation:

If the DME control unit has been replaced, it will also be necessary to carry out adjustment of the injectors!

Injection quantity compensation is carried out with the aid of so-called adjustment values.

The adjustment values are printed in two blocks of three digits on each injector.

The adjustment values must be stored in the new control unit!

If injector quantity compensation is not carried out, the engine may run roughly or fail to start.

Fig 3: Identifying Injector Adjustment Values

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Read off the adjustment values and enter according to the installation location (cylinder) of the injectors:

NOTE: Check stored fault message.
Delete fault memory.