If none of the fuses are blown, then the drivers door latch may have failed electrically causing the door not to open. The bmw technician will need to scan the vehicle for fault codes, and try to activate the drivers door lock using the scan tool. If this doesn't work either. They will need to remove the door panel with the door closed to access and replace the latch assembly. The latch cost is about $130, plus about 2-3 hours labor for diagnosis and replacement, depending on how far they need to go.
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You could always roll down the window, use the mechanical key to unlock the door and then pull the outside handle to open the door.----------
It is a rather common problem. If you read part of SI B51 19 07, you can see they are replacing the 15 amp fuse with a 20 amp fuse. Also, you can see they warn against using spraying any silicone products into the door latch.
CAUSE
This is due to a blown fuse in the JBBF caused by either:
An excessive amperage draw by one of the door lock actuators, which is commonly attributed to silicone contamination; or
An intermittent, but acceptable, amperage spike slightly above 15A, due to normal variation in the locking system.
CORRECTION
Replace the fuse with one of a different rating.
Replace the necessary actuator as well, but only if it is drawing excessive amperage.
NOTE: Never spray any silicone products into the latch, as this will lead to premature failure.
PROCEDURE
Perform a vehicle test using ISTA.
Inspect fuse 57 (up to 9/07 production) or 73 (from 9/07 production) in the JBE.
Replace the blown 15A fuse with a 20A fuse.
Perform a function test by activating the door locks 10 times in succession via the central locking switch.
CAUSE
This is due to a blown fuse in the JBBF caused by either:
An excessive amperage draw by one of the door lock actuators, which is commonly attributed to silicone contamination; or
An intermittent, but acceptable, amperage spike slightly above 15A, due to normal variation in the locking system.
CORRECTION
Replace the fuse with one of a different rating.
Replace the necessary actuator as well, but only if it is drawing excessive amperage.
NOTE: Never spray any silicone products into the latch, as this will lead to premature failure.
PROCEDURE
Perform a vehicle test using ISTA.
Inspect fuse 57 (up to 9/07 production) or 73 (from 9/07 production) in the JBE.
Replace the blown 15A fuse with a 20A fuse.
Perform a function test by activating the door locks 10 times in succession via the central locking switch.
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The Junction Box Electronics (JBE).the JBE or Junction Box Electronics. This is the main "body module" and handles all of the power control functions in the car.
WHEN A DOOR LOCK ACTUATOR FAILS AND BLOWS A FUSE? THIS IS A COMMON EVENT ON THE 2007 328 MODEL. WHAT HAPPENS IS A POWER DOOR LOCK ACTUATOR FAILS DURING THE UNLOCK PROCESS AND THE INCREASE IN AMPERAGE CAUSES 2 FUSES TO BLOW. THIS PREVENTS ANY OF THE CAR'S DOOR LOCKS FROM OPENING, THEREBY TRAPPING OCCUPANTS IN THE VEHICLE. THERE IS NO WAY TO UNLOCK THE DOORS FROM INSIDE THE VEHICLE. OCCUPANTS MUST EITHER CLIMB OUT OF A WINDOW OR HAVE SOMEONE UNLOCK THE CAR USING A MECHANICAL KEY FROM OUTSIDE OF THE CAR.
ELECTRONIC DOOR LOCKS WOULD NOT UNLOCK. NO DOOR COULD BE UNLOCKED FROM INSIDE VEHICLE. NO DOOR COULD BE OPENED FROM INSIDE VEHICLE. PULLING THE INTERNAL DOOR LATCH REPEATEDLY FAILED TO UNLOCK OR OPEN DOOR. PUSHING ELECTRONIC LOCK/UNLOCK BUTTON ON DASHBOARD FAILED TO UNLOCK DOORS. LOWERING WINDOW AND USING MANUAL KEY IN EXTERIOR LOCK UNLOCKED DOOR BUT AS SOON AS KEY WAS ROTATED TO REMOVE FROM LOCK DOOR IMMEDIATELY ELECTRONICALLY RELOCKED. KEY HAD TO BE HELD IN UNLOCK POSITION WHILE INTERIOR DOOR LATCH WAS USED TO OPEN THE DOOR IN ORDER TO OPEN DOOR TO EXIT CAR. SUBSEQUENTLY EXCEPT FOR DRIVER'S DOOR ALL DOORS REMAINED INOPERABLE LOCKED BUT DRIVERS DOOR COULD BE OPENED ONLY MANUALLY WITH MANUAL KEY FROM EXTERIOR OR LATCH FROM INTERIOR WITHOUT AUTOMATICALLY RE-LOCKING. DEALER WAS NOTIFIED AND REPAIRED. DEALER REPORTED THAT A "SHORT" HAD CAUSED FAILURE OF ABILITY TO UNLOCK. EVENT HAS NOT OCCURRED AGAIN IN ONE MONTH.
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This same problem is faced by many other bmw 328xi users.The service cenmter has not still declared this problem as recall.Click this link below and go through the other users comment on this problem:---