12 14 550 Replacing control unit (DME) (N54)

WARNING: This page is about a different car, the 2013 BMW Z4, 2012 BMW Z4, 2011 BMW Z4, 2010 BMW Z4, and 2009 BMW Z4. However, it is still accessible from the selected car via links, so may be relevant.

IMPORTANT: Read and comply with notes on protection against electrostatic damage (ESD PROTECTION (ELECTRO STATIC DISCHARGE) )

Necessary preliminary tasks

Turn off ignition
Disconnect BATTERY NEGATIVE LEAD

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 adjustment (description at end of instruction).

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.

Release bolts along line (1).

Tightening torque 12 90 1AZ .

Remove electronics box cover.

Fig 1: Identifying Electronic Box Cover Mounting Bolts

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Unlock battery positive lead (1), detach and lay to one side.

Release locks (2) in direction of arrow and pull control unit upwards slightly.

Fig 2: Opening Control Unit Locks

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Pull control unit (1) upwards slightly until plug (2) can be released from control unit in direction of arrow.

Unlock plug (2) and detach from control unit (1).

Fig 3: Pulling Control Unit Upwards

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Lift out control unit (1).

Fig 4: Lifting Control Unit

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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 5: Identifying Adjustment Value Printed In Blocks Of Digits On Injector

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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 DIS Tester
Identify car
Select "Function selection"
Select "Service functions"
Select "Engine electronics"
Select "Adjustment programs"
Select "Adjust injectors"
Select "Test schedule"
The adjustment value must be entered for each cylinder.

Fig 6: Identifying Adjustment Value Printed In Blocks Of Digits On Injector

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NOTE: Check stored fault message.
clear fault memory.