12 14 550 Replacing control unit (DME)

Necessary preliminary work:

Switch off ignition.
Clamp off BATTERY .
Remove MICROFILTER HOUSING .

IMPORTANT: Follow instructions for REMOVING AND INSTALLING CONTROL UNITS .

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

Replacement:

CARRY OUT PROGRAMMING/ENCODING .

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

Unlock locks (2) in direction of arrow.

Remove cover (3).

Fig 1: Identifying Control Unit Box Cover Fasteners With Locks

Courtesy of BMW OF NORTH AMERICA, INC.

Unlock connector (1) and remove.

Release grommet (2) from electronics box.

Installation note:

Make sure grommet (2) is correctly seated in housing (watertightness).

Unlock control unit (3) and raise slightly.

Fig 2: Identifying Unlock Control Unit, Connector And Grommet

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Unlock connectors (1) using slide in direction of arrow and remove.

Remove control unit (2).

Installation note:

Replacement:

Note control unit identification number and encoding.

Fig 3: Removing Control Unit

Courtesy of BMW OF NORTH AMERICA, INC.

NOTE: Check stored fault messages.
Delete fault memory.

Necessary preliminary tasks:

Switch off ignition.
Disconnect BATTERY EARTH LEAD .
Remove MICROFILTER HOUSING .

IMPORTANT: Follow instructions for REMOVING AND INSTALLING CONTROL UNITS .

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

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

Unlock locks (2) in direction of arrow.

Remove cover (3).

Fig 1: Identifying Control Unit Box Cover Fasteners With Locks

Courtesy of BMW OF NORTH AMERICA, INC.

Unlock connector (1) and remove.

Release grommet (2) from electronics box.

Installation note:

Make sure grommet (2) is correctly seated in housing (watertightness)!

Unlock control unit (3) and raise slightly.

Fig 2: Identifying Unlock Control Unit, Connector And Grommet

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Unlock connectors (1) using slide indirection of arrow and remove.

Remove control unit (2).

Installation note:

Replacement:

Note identification number and encoding.

Fig 3: Removing Control Unit

Courtesy of BMW OF NORTH AMERICA, INC.

Injector adjustment

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

Injector adjustment 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!

Fig 4: Identifying Injector Label

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

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

Connect BMW diagnosis system
Identify vehicle
Select "Function selection"
Select "Service functions"
Select "Engine electronics"

Fig 5: Identifying Injector Label
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Select "Adjustment function"
Select "Adjust injectors"
Change "Test schedule"
The adjustment value must be entered for each cylinder.

NOTE: Check stored fault message.
Delete fault memory.