Removal and installation the DME control unit (BMW 3 Series E36)

Note: Each control unit is programmed for certain basic parameters, which are only average values. The control unit receives different input values from the sensors, depending on the engine condition, which are compared with the values stored in the unit. In accordance with these, the control signals of the unit change. New values are stored, which corresponds to the "learning process".

If the DME control unit is without power supply for more than one hour (the block is removed or the battery is disconnected), then the self-learning system loses the remembered values.

When reinstalling a unit with erased information or installing a new unit, the system must remember the input values again. This process can cause uneven engine operation and engine braking problems. In order to compare all engine condition parameters, it is necessary to drive the car for several minutes at variable speed.

Removal

Before removing the control unit, it is recommended to conduct a survey and printout of the stored faults at a BMW service station. This will determine the type of defect.

Turn off the ignition. Disconnect the ground wire from the battery.

Caution: When the battery is disconnected, the information in the electronic memory devices, such as the engine fault memory or the radio security code memory, is erased. Disconnect the battery only when the ignition is off, so as not to damage the fuel injection system control unit. When disconnecting the battery, follow the instructions in the sections "Radio" and "Removing and installing the battery".

If the battery is located in the engine compartment, remove the battery.



Release the 3 upper spacer clamps by using a screwdriver to pull out the clamp rod and then the clamp itself.

Unscrew the 2 lower plastic nuts, see picture. Remove the rubber cover.



Unscrew 3 bolts and move aside the cover with the cable harness.

Fold back the connector locking clip and remove the connector.

Pull the control unit out of the mounting brackets. It is not necessary to unscrew the mounting bracket bolts.

Note: If you have an automatic transmission, there is another control unit above the DME control unit.

Installation

When purchasing a new unit, please indicate the control unit number and its coding. It is recommended to take the removed control unit with you.



Push in the control unit. Connect the connector. Close the locking clips.

Place the pads.

Install the battery.

If the control unit has been de-energized for more than 1 hour, or if it is a new unit: Warm up the engine to operating temperature. Perform a test drive at variable speed for about 10 minutes. In this case, the control unit "learns" the engine parameters.