Flat key fob battery

Malcyb

Member
Yesterday morning my wife tried to set off for an appointment in a hurry and found that her remote key fob didn’t work any more. Not only that, but it wouldn’t even unlock the door manually - she swears blind she turned it the right way. It turned in the barrel but didn’t do anything. So she borrowed my key and that was all good. I replaced the battery in her’s and when she returned I went through the resync sequence so it’s working fine again.
All good... however it seems she was very lucky the battery didn’t give out when she was a long way from home. My question is, is there anything you can do in that situation, or are you just locked out of the car? In the meantime I think I’d better get a new battery for mine very quickly, just in case....
 
The key should work in the door even if the battery is flat. Try it again and then try passengers door. Mechanism might need a lubrication as it's seldom used.
 
The key should work in the door even if the battery is flat. Try it again and then try passengers door. Mechanism might need a lubrication as it's seldom used.
A2 only has a barrel in the drivers door, as I've found to my cost(on more than one occasion due to the relatively small drive I have 5 A2s squeezed into, coupled with the occasionally long time between starts).
You are correct though, the key should work though sometimes the alarm will sound after manually unlocking and opening the door until the ignition is switched on. Also, always worth repeating, in case of emergency, break an opening window, the small ones are much more difficult /expensive to replace.
 
Strange that the key failed to open the car. Maybe you should remove the battery from the key in question and try again to see if it opens the car as mine came with a broken remote but the key still opened that driver's door.

I keep a spare battery in the glove box for all my cars knowing that the key will open the door, even it the alarm then goes off whilst I am fighting with the battery cover

Cheers
Simon

P.S. In case of emergency, don't break a window at all, call a locksmith, or better & cheaper yet, call a taxi to take you to a supermarket to buy a new battery or your other half to bring you the other key.
 
The battery plays no part in the opening of the door with the key. Battery replacement will not give you access to the car, the remote needs to be paired following battery replacement.
Various options for this though all require access to the ignition. My process...
Open drivers door. Insert key in ignition. Turn ignition on then off. Remove key then press a button on the remote. Always works for me.
 
Replace remote batteries every year and at the same time lubricate the lock in the drivers door and check it manually locks and unlocks the car. Using the key in the door does not turn off the alarm. You need to insert the key in the ignition and turn on within about 5 seconds.
No second key? Then you are just asking for trouble. At a minimum have a valet key to get your locked keys out of the car. Far cheaper than a locksmith or replacement window.
 
Agreed
The battery plays no part in the opening of the door with the key. Battery replacement will not give you access to the car, the remote needs to be paired following battery replacement.
Agreed, my suggestion of removing the battery and testing the door lock was more to recreate the original scenario, but as you say, the fact that there is a fresh battery fitted and the fob has been re-paired to the car again should make no difference to the lock operation.

Really what I was saying was....test the key in the lock to see if it was operator error or there is a mechanical issue with the lock mechanism which was only discovered when the key needed to be used.

Cheers
Simon
 
The key barrel in the driver’s door should have a mechanical connection to the lock. On RHD A2s, to unlock the car, you turn the key to the right (towards the front of the car), and then back to centre. Any rotation to the left (to the rear of the car) will just lock the door again.
A problem arises when inexperienced people change the driver’s door lock (to remedy a failed microswitch, for instance), as they sometimes fail to reconnect the mechanical connection between the key barrel and the locking mechanism. This can lead to a situation where a dead car battery or a dead key battery means the car can no longer be unlocked.
I suggest you try to unlock the car manually using the driver’s door barrel. If you suspect that the mechanical link to the lock itself is disconnected, it needs dealing with sooner rather than later.

Cheers,

Tom
 
A2 only has a barrel in the drivers door, as I've found to my cost(on more than one occasion due to the relatively small drive I have 5 A2s squeezed into, coupled with the occasionally long time between starts).
You are correct though, the key should work though sometimes the alarm will sound after manually unlocking and opening the door until the ignition is switched on. Also, always worth repeating, in case of emergency, break an opening window, the small ones are much more difficult /expensive to replace.
To add to the collective "worthless knowledge" bank I can contribute with the fact that those A2s that were not built with remote locking instead have an additional barrel, in the passenger door.
Not that this helps in the topic of this thread though ? :)
 
To add to the collective "worthless knowledge" bank I can contribute with the fact that those A2s that were not built with remote locking instead have an additional barrel, in the passenger door.
Not that this helps in the topic of this thread though ? :)
This is indeed correct. In the UK, all A2s were made with remote central locking (even the most basic models), so this is not widely known here.

Cheers,

Tom
 
Replace remote batteries every year and at the same time lubricate the lock in the drivers door and check it manually locks and unlocks the car. Using the key in the door does not turn off the alarm. You need to insert the key in the ignition and turn on within about 5 seconds.
No second key? Then you are just asking for trouble. At a minimum have a valet key to get your locked keys out of the car. Far cheaper than a locksmith or replacement window.
Thanks for the replies everyone. I’ve just tried my key and, sure enough, a clockwise turn in the drivers door and return to original position does unlock it. I’m not about to try removing the battery as my wife’s gone away for the weekend with her key, but perhaps I’ll try that when I have a chance though sounds like it shouldn’t make any difference. So I’m a bit mystified really... maybe it was operator error after all, though I wouldn’t dare suggest that to her.
can I just check, are you saying that even if the fob battery is flat, putting the key in the ignition and turning on in 5 seconds will turn off the alarm? presumably it won’t actually start the car until it’s got a new battery and resynced.
 
can I just check, are you saying that even if the fob battery is flat, putting the key in the ignition and turning on in 5 seconds will turn off the alarm? presumably it won’t actually start the car until it’s got a new battery and resynced.
The battery in the key is required to operate the remote central locking, but not to start the car. You can take the battery out of the key and it'll still start the car. :)
 
The battery in the key is required to operate the remote central locking, but not to start the car. You can take the battery out of the key and it'll still start the car. :)

Ah my ignorance, I thought there was some kind of transponder in the key and imagined it might need a battery to be detected.
 
Can I just check, are you saying that even if the fob battery is flat, putting the key in the ignition and turning on in 5 seconds will turn off the alarm? presumably it won’t actually start the car until it’s got a new battery and resynced.

The battery in the fob only provides power for the remote lock / unlock functions, which requires synchronisation each time the battery is replaced.

The transponder in the key which links to the immobiliser does not require a battery in the fob, and the key will be fully operational in the ignition regardless.
 
Ah my ignorance, I thought there was some kind of transponder in the key and imagined it might need a battery to be detected.
The transponder in the key is an entirely passive device; it doesn't need its own source of power to be readable to the immobiliser.

So I’m a bit mystified really... maybe it was operator error after all, though I wouldn’t dare suggest that to her.
I was once called out to my friend's mum's house because she couldn't get into her A2. When I turned the key in the lock and opened the door, she swore blind that it just would not work for her. I've no doubt she'll have succeeded in unlocking the door many times, but will also have been locking it again each time, simply due to an incorrect motion of the key within the barrel.
The link between the key barrel and the locking mechanism is extremely simple. There's no way it'll have worked for you and not for your wife. Operator error is, I'm afraid to say, almost certainly the explanation here.

Cheers,

Tom
 
If you do get completely stuck due to a flat coin cell battery and you only need it to work another couple of times then try warming up the coin cell.

At lower temperatures the chemistry slows so the ability to provide peak current is compromised. A ‘burst’ of transmission can fail because it exceeds the peak current capacity.

If the coin is freezing cold stick it in a pocket for a bit then try it again.

Not so relevant when you can just use the key in the door lock but it helped me with an old Celica where the key broke... in the snow...


Sent from my iPhone using Tapatalk
 
Back
Top