Locked out, Battery Dead, Both keys Dead.

[ZLuke]

Strange the manual key doesn't work! When my battery died I could still manually unlock the drivers door. I took my battery out completely and could still lock/unlock drivers door with physical key.

When the battery first died I could still used the key to manually open the door as well, however ever since the KEY died I have been unable to.

I've been unable to find any info where both the car battery and the key have both been dead so unsure if the dead key is the reason.

Hopefully once the battery is charged/replaced the doors will respond again. Otherwise I'm locked out

[ZLuke]

Hi guys,

Thanks to everyone who helped out.

Thought I best update and keep you all posted incase the same happens to anybody else.

Once I changed the battery I could fianlly open the doors manually with my dead keys (I have no idea why or how it works that way) also managed to charge the keys in the ignition, and now all everything is fine and dandy!

Happy days,

Cheers again for all the advice....... (not the break your window to get in obviously, you know who you are )

Luke

[Liam-O]

How did you get in to change the battery if the locks wouldn't work?

[ZLuke]

How did you get in to change the battery if the locks wouldn't work?

I posted on page 2 before explaining, the one previous owner had never (ever) used the keys manually to unlock the boot, always the fob. Somebody told me to apply some wd40 and fiddle the key until it freed up. And that worked.

Cheers

[Anotheroldguy]

We had this problem with a completely dead car battery and non-functioning keys with my son's Z4 after it had been laid up during lock-down. The back-up blade key inside the cartridge key did not seem to be doing anything when I turned it in the lock. I was about to break a window to gain access when, out of frustration, I waggled the key backwards and forwards in the lock. After about 20 turns, I noticed the button in the door capping was starting to come up. Eventually it came fully up and I was able to open the door.

Further points to note: (i) the car battery can then be re-charged by using the terminals under the bonnet - the charger should not be connected directly to the battery. Apparently this damages the car's electronics. (ii) some BMW cartridge keys have an exchangeable battery inside - these have a flap to access the battery. If it doesn't have a flap then don't use a Stanley knife to open it up (as I did) - the re-chargeable cell inside is sealed in and is non-exchangeable. I left the key hidden inside the car while the car battery was re-charging and it re-charged at the same time. (iii) in the event of a further lock-down, use a battery conditioner to stop the battery running down!

[MrPT]

Had no idea that it was possible for manual key opening to not work.

Worst comes to worst you can always remove the rear bumper and stick your hand through the side vent to open the boot from the inside. Doesn’t take long.

[colb]

The battery in the keys are used for the central locking functions not the EWS chip inside the key, that is simply read with the key in the ignition switch by a loop aeriel inside and around the ignition switch. If the key batteries are both flat you might get them recharged by placing them on a toothbrush charger overnight., worth a try. Otherwise you have to cut the keys open to get at the battery. There are places that refurb keys, might be worth taking that route one key at a time. As others have said the keys should unlock / lock the doors manually, same for the boot, if they don't then maybe a link inside the door has become disconnected as its purley a manual operation.

[rdm05z4]

Not everyone has this option. But I am lucky to have a garage and for this exact issue never lock my cars in the garage.

[enuff_zed]

Not everyone has this option. But I am lucky to have a garage and for this exact issue never lock my cars in the garage.

I guess it would depend on the exact car and it's characteristics, but I have been told if you don't lock the car it won't 'go to sleep' properly and creates a slight drain on the battery?
Because of this I've always locked mine (after connecting the Ctek), so have no evidence whether this is fact or fiction.

[Deeznutzs]

I had the same dead battery issue and I was unable to unlock my 2016 Z4 with both key fobs and the integrated metal key.
I thought I’d post how I eventually got the car to unlock to help someone in the same situation.
I have comfort access so I was able to change the batteries in the key fobs but none of them worked. I tried to open the door several times with the metal key but it remained locked. I finally got it to open by applying constant pressure on the metal key as I turned it to the left or anti-clockwise. At the same time, I kept the door handle up. There’s an initial point where it feels like you can’t turn the key anymore but applying more force makes it turn slightly further. The door finally opened for me hand I was able to gain access to the hood and charge the battery.

[weegeoff]

Go in through the flap that you change your headlight bulb {right side] you can see the wires that pop the bonnet they are in black sheathing Give them a tug and the bonnet should pop. It is easier to get to if you take the wheel off. Your alarm might go off when you tilt the car. You can then charge the battery