12 14 550 Replacing control unit (DME) (N20)

WARNING: This page is about a different variant/trim than selected.

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

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 and pull off all connectors (1) from the DME control unit (2).

Release screws.

Tightening torque 12 14 1AZ .

Remove DME control unit.

Fig 1: Locating DME Control Unit Screws

Courtesy of BMW OF NORTH AMERICA, INC.

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 value is printed on each injector in three digits.

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.

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

Fig 2: Identifying Cylinder Adjustment Value

Courtesy of BMW OF NORTH AMERICA, INC.

NOTE: Check stored fault message.
Delete fault memory.