Battery failed, manual key won't unlock door

[dubois]

2013 BMW 120D Xdrive M Sport. F20
Battery completely dead after period out of use. Key from the remote will turn but won't lift button inside driver's door.
Dealer suggests RAC recovery to them, they would probably break a window to get in.
Other suggestions
(1) Jack up, remove undertray, connect battery charger to starter motor feed.
(2) Break into air inlets to access bonnet release.
(1) is difficult due to (very!) old age. (2) uncertain of detailed procedure.
Any other ideas, gents?
Or details of (2), please.

[Tyre Smoke]

Your opening post on this forum is essentially asking how to break into a BMW.

Best of luck with that.

Why won't the key lift the button?

Suggest you get it recovered to your local BMW dealer/specialist or get a mobile locksmith involved. I doubt anyone here is going to give detailed advice on how to break in.

[Simes205]

Turn the key harder.

[Locknut]

Simes205 said:

Turn the key harder.

I agree with that, but before you do, use a straw to spray some WD40 or similar into the lock via the key-hole.

[dubois]

Sorry, Tyre Smoke, if my opening post gave the wrong impression.

The BMW dealer Technician said that key should turn about 45 degrees clockwise (rhd car) and then lift the button. The key easily turns that amount but no further, despite persuasion with pliers. A "deadlock" operation was mentioned but discarded (perhaps rather too quickly) as a possible explanation.

I've tried both keys, both ways up, turning clock & anticlock-wise, with & without lifting door handle, both before & after key operation.

Is it possible that a deadlock system in fact exists and has been triggered in some way by my flat battery?

Not surprisingly, operation of the mechanical key has never been checked (ex demo car). Followers of this post might like to check it works on their car - no need to run your battery down, if you do be sure to leave bonnet open!

There is no evidence that the lock itself is at fault.

Thanks, Simes205 for your suggestion, but I've tried that.

Also thanks, Locknut, I'll try WD40, but lock operates easily.

I might pursue option (1) above - jack up, remove undertray to access starter - with some younger person's assistance.

My Haynes manual (for previous 1 series cars) is locked in the car; can some knowledgeable gent please confirm that my (2013 BMW 120D Xdrive M Sport) starter is readily accessible this way?

I've done virtually everything on my cars for over 60 years, including engine rebuilds and competition preparation, and don't like being beaten. In contrast, no work on BMW save changing headlamp bulbs; servicing at dealer's - 5 year plan supplied with the car.

Finally, is there Manual and/or Parts Catalogue available (online?) for 2013 models?

[Matt_E_Mulsion]

I bet the lock just needs more lubrication and a harder turn, especially if it hasn't been used in 6+ years. I'd go with powering up some of the electrics and popping the central locking open on the keyfob as the next plan.

[BFleming]

dubois said:

Finally, is there Manual and/or Parts Catalogue available (online?) for 2013 models?

RealOEM.com for parts
newtis.info for manual

I'm suggesting calling an auto locksmith for this one, someone local to you. He will get into the car in about 10 seconds (best you look away) without damage and then you can get the bonnet open. You can then attach jump leads to the positive point under the bonnet, and get the rest of the car open.
If charging the AGM battery, use a charger suitable for this purpose. If replacing the battery, buy the appropriate AGM one, and have it registered to the car.

[helix402]

Do you have a BMW Emergency Service subscription? I used to work for them. Their Technicians will be able to quickly access your car without damage and arrange recovery to a dealer if you want.

[isleofthorns]

this used to happen on my old e39 5 series.

i got around it by taking out the number plate bulb and connecting a battery trickle charger across the pins... this seemed to give it enough juice to allow the remote central locking to work

[dubois]

Thanks very much gents Matt_E_Mulsion, BFleming, helix402 and isleofthorn.

The manual/parts will be invaluable. My charger will deal with the AGM battery safely - 14.8 volts maximum charge if I remember.

I don't subscribe to BMW Emergency Service, but wonder if RAC Homestart might assist with an auto locksmith. Is it really a 10 second job?

The number plate bulb trick will only work (I think) if you ran the battery down by leaving the sidelights switched on.

Thanks again everyone. I'll report back.

[Oilchange]

isleofthorns said:

this used to happen on my old e39 5 series.

i got around it by taking out the number plate bulb and connecting a battery trickle charger across the pins... this seemed to give it enough juice to allow the remote central locking to work

Ingenious!

[dubois]

Success, with a squirt of WD40 and turning the key with a small adjustable spanner, easier to judge the torque on the key.

After getting a new AGM battery, I shall be turning the key from time to time to check. Suggest this is a GOOD IDEA for everyone, say at Mot time.

Thanks to all who helped.

[BFleming]

New battery registered?