12 14 550 Replacing Control Unit (DME)

Necessary preliminary tasks: 

• Switch off ignition
• Disconnect battery
• Remove microfilter housing

Replacement: 

• Carry out programming/coding
• Carry out injector quantity adjustment (description at end of instruction)

Switch off ignition.

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

Unlock locks (2) in direction of arrow.

Remove cover (3).

Unlock plug (1) and remove.

Release grommet (2) from electronics box.

Installation: 

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

Unlock control unit (3) and raise slightly.

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

Remove control unit (2).

Installation: 

Replacement:

Note device identification number and coding.

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!

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 DIS Tester
• Identify car
• Select "Function selection"
• Select "Service functions"
• Select "Engine electronics"
• Select "Adjustment programs"
• Select "Adjust injectors"
• Change "Test schedule"
• The adjustment value must be entered for each cylinder.
  Fig 5: Identifying Installation Location (Cylinder) Of Injectors

  Courtesy of BMW OF NORTH AMERICA, INC.