12 14 550 Replacing control unit (DME) (N20 hybrid drive)
Compliance with the following points is mandatory before beginning work:
- Observe SAFETY INFORMATION for working with electric vehicles.
Necessary preliminary tasks:
- Switch off ignition.
- Disconnect BOTH BATTERY EARTH LEADS .
- Remove ACOUSTIC COVER
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).
Switch off ignition.
Removal:
Unlock and pull off all connectors (1) along the arrow.
Loosen the screws along the arrows.
Remove DME control unit (1).
Installation:
Install DME control unit.
Tighten screws along arrows.
Tightening torque 12 14 1AZ .
Connect and lock all connectors (1) along the arrows.
All connectors (1) must engage audibly.
Required follow-up work:
- Install the ACOUSTIC COVER .
- Connect BOTH BATTERY EARTH LEADS .
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 with three digits - depending on the version - on the injector body.
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:
- Connect BMW diagnosis system
- Identify vehicle
- Select "Function selection"
- Select "Service functions"
- Select "Engine electronics"
- Select "Adjustment function"
- Select "Adjust injectors"
- Select "Test plan"
- The adjustment value must be entered for each cylinder.