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BMW 3 (E90) 320d




A6D4 - Central locking relay. Unlocking.

A6D5 - Central locking relay. Locking.


Fault codes recorded in the junction box control unit(JBBF).
Improper operation of the central locking.

The following symptom is observed in the workshop:
- If we check the amperage of the fuses F56, F57 or F73, depending on vehicle's year of manufacture, which supplies the central locking system, it is 15 Amp. It must be a 20 Amp fuse.

NOTE: This technical note only affects those vehicles that are within a specific manufacturing date.


Possible causes:
- Incorrect central locking fuse. The current one is 15 Amp and it must be a 20 Amp fuse.
- Defect in the front door locks.
- Defect in one or two of the rear door locks.


Repair procedure:
- Read the fault codes recorded in the junction box control unit (JBBF) using the diagnostic tool.
- Confirm that the fault codes are the same as the ones that appear in the field symptoms of this bulletin.
- Check the fuse F56, F57 or F73 for the central locking system depending on the manufacturing year of the vehicle.
- Replace the F56, F57 or F73 fuse with a 20 Amp fuse.
- Check the proper operation of the central locking system by locking and unlocking it up to 10 times.
- Check the proper operation of both front and rear locks.
- Replace both front door locks with a modified version which are included in a repair kit, if it is necessary.
- Replace the rear door lock which does not work properly, if it is necessary.
WARNING: If the central locking system is locked and unlocked more than 15 times, the key/locking command will be deprogrammed.

See image 1:
A - Location of the control unit junction box (JBBF).

See image 2:
- (S47) Driver's side locking system.
- (S49) Passenger's side locking system.
- (M14a) Locking system of the rear right door.
- (M15a) Locking system of the rear left door.