[VP Electricity]

This morning my 2007 E91 wouldn't unlock the doors - via CA, nor keyless unlock button, nor Central Lock button on the dash (lock worked fine).

A search showed a number of threads on this issue. Apparently there is a TSB:

You might need a FB map:



However, a couple of points:

1) My DOM was 6/07, but my fuse for unlocking (15A, blown as expected) was in position number 73 (just adjacent to the fuse puller tool) - which it wasn't supposed to be per the TSB until DOMs 9/07 and later.

2) Since you can't get the passenger door open, you have to do it from the driver's side. Since I'm six foot, I didn't climb into the passenger seat, I leaned over the center console. The fuses are tough to reach and I should have tossed a blanket over the console - I think I bruised my delicate rib cage

3) 15A fuse for FOUR actuators? Upgraded to 20 (per the TSB)? A door unlock pulse is about 800 milliseconds. To pop a 15A MiniATC fuse, that's a lot of inrush current. Surprised this doesn't seem to happen more often in cold weather (inrush currents are often higher when the winding is cold IIRC).

Per this fuse spec, a 15A fuse should take about 27A for 800mS.

When I was at DEI, in the 90's, we used a rule of thumb of 7.5A of fuse per actuator. That meant that for four-door actuator installs, we recommended 30A fusing. Are BMW actuators really 33% more efficient than Tech-Cast actuators? (TSB recommends AGAINST lubricating the door latch mechanism, saying it will cause premature failure, but it only mentions silicone lubricant - no mention if other forms of lube will do the same thing).

Conclusion: Get a spare 20A MiniATC. If your car stops unlocking, you know what to do to get it working again. But if you're under warranty, I'd get that event on record, so you have a chance of getting new actuators before the warranty runs out.

[fdriller9]

You couldn't use your actual metal key inside the fob to open the doors either?

[VP Electricity]

Originally Posted by *********

You couldn't use your actual metal key inside the fob to open the doors either?

I could open the driver's door. But apparently the others were deadbolted, as I couldn't even open them from the inside (and of course the only door with a key cylinder is the driver's door).

Just got a call from my dealer - they VOLUNTEERED to swap both front latch/actuators. Going in next week!

[fdriller9]

Hmm...yea I guess you would still need the actuators to open the other doors; from the driver's door key slot.

At least the dealer is replacing them for free!

[808MGuy]

That's odd that you couldn't even open it with the interior handle. I would think that is not allowed to happen as it is a potential safety hazard.

[scooby9]

This has happened to me twice. Coincidentally on long road trips.

Rolled down the driver window and used the key to get out.

The dealer replaced all of my actuators but I still keep spare fuses in the glove box just in case.

[skinrock]

Originally Posted by 808MGuy

That's odd that you couldn't even open it with the interior handle. I would think that is not allowed to happen as it is a potential safety hazard.

Bringing back from the dead. I'm wondering if there is any clarification on this. I just ran into the same issue and found my #57 fuse to be blown. I'll be replacing it in a couple days, but this was the first thing I noticed...only my driver's side door unlocks from the inside.

Is this by design or a sign of other issues? I find it very disturbing they would use the actuator to unlock the door when pulling the handle manually...this seems extremely hazardous.

[VP Electricity]

Originally Posted by skinrock

...only my driver's side door unlocks from the inside.

Is this by design...

I find it very disturbing they would use the actuator to unlock the door when pulling the handle manually...this seems extremely hazardous.

Well, then, get disturbed.

For years BMW has used a two-stage locking process. If you press lock once on their remote, you lock the doors, but you can still open them from inside. If you press lock twice in quick succession, you engage a deadbolt which disables opening the door from the inside. (If the car has CA, the fob must be outside the car).

This prevents window-breakers from being able to open the door. If you can't open the door from the inside, it's because the unlock fuse blew, and you inadvertently did a double-lock-press and engaged the deadbolts (like I did).

Their real mistake (other than the 15A fuse rating in the first place) was in having a separate lock and unlock fuse - allowing deadbolts to be engaged after the unlock fuse has already blown. BOTH LOCK AND UNLOCK CAN'T HAPPEN AT THE SAME TIME - why give them separate fuses? The same fuse should power lock and unlock, and then the odds of this happening would be, shall we say, remote.

[skinrock]

More questions about this:

If the fuse blows, does it make sense that I can't unlock the trunk, even with the key?

Also, some weird things happened tonight. I replaced the fuse, and it worked fine at the auto store and when I got home. Then I loaded up my suspension in the trunk, and it started acting weird again. Now it won't unlock, but the fuse didn't blow, and the trunk still seems okay.

Basically all I'm concerned about right now is showing up at the shop tomorrow and not being able to open the trunk. So far it seems okay, and I'm hoping I can just make it there and open it and worry about it later. Any thoughts?

[BMW owner]

Originally Posted by VP Electricity

Well, then, get disturbed.

For years BMW has used a two-stage locking process. If you press lock once on their remote, you lock the doors, but you can still open them from inside. If you press lock twice in quick succession, you engage a deadbolt which disables opening the door from the inside. (If the car has CA, the fob must be outside the car).

This prevents window-breakers from being able to open the door. If you can't open the door from the inside, it's because the unlock fuse blew, and you inadvertently did a double-lock-press and engaged the deadbolts (like I did).

Their real mistake (other than the 15A fuse rating in the first place) was in having a separate lock and unlock fuse - allowing deadbolts to be engaged after the unlock fuse has already blown. BOTH LOCK AND UNLOCK CAN'T HAPPEN AT THE SAME TIME - why give them separate fuses? The same fuse should power lock and unlock, and then the odds of this happening would be, shall we say, remote.

Sounds like I did the same thing by pressing twice and engaging the deadbolt. Were you able to fix this by replacing the fuse with a 20A? My windows will still go up and down when I press and hold the unlock buttons but can only open door from outside with the key.

[rollinstone157]

Originally Posted by VP Electricity

Well, then, get disturbed.

For years BMW has used a two-stage locking process. If you press lock once on their remote, you lock the doors, but you can still open them from inside. If you press lock twice in quick succession, you engage a deadbolt which disables opening the door from the inside. (If the car has CA, the fob must be outside the car).

Do you know if newer models do this?? I tried it in my car and a passenger was able to open the door from the inside. Maybe a fuse has blown?

[zachar3]

Wait,
Is the deadbolt thing whats causing the issue? Is it that once you close the deadbolt you cant disengage it?

[skinrock]

Originally Posted by zachar3

Wait,
Is the deadbolt thing whats causing the issue? Is it that once you close the deadbolt you cant disengage it?

No, the deadbolt just complicates the issue. If you blew the fuse, you can still unlock the driver's door manually by pulling the handle from within. If you double lock and engage the deadbolt (while you're inside obviously), you can't unlock it unless you roll down the window and use the physical key.

[zachar3]

And how quickly do you need to press the lock button to engage it?

[zachar3]

and is the deadbolt disengaged with the unlock button on the key?

[skinrock]

Originally Posted by zachar3

And how quickly do you need to press the lock button to engage it?

Not sure what the threshold is, I imagine not more than a minor delay between pushing the button twice.

Originally Posted by zachar3

and is the deadbolt disengaged with the unlock button on the key?

Yea, when the fuse is fine. That's the problem, though - if the fuse is blown, the deadbolt prevents you from using the handle on the inside.