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Key not working

S

Sticks

Active member
Kent
Because of the awful weather followed by the current situation and waiting to get a water leak repaired, my 04 3.0SE hasn't had much use for a few months. I've started it, run it around the block, cleaned it and it's been on a Ctek.

Now I find that although both keys will open it, and turn on the ignition, only one will crank and start the car. Carly gives me an error code of 0027A4.

From what I've read, I guess the offending key has lost it's connection with the car (DME-EWS interface?) due to a discharged key battery. I've charged it on a toothbrush charger for 24 hours but still no joy. I'd have thought that it would have stopped unlocking the car before losing this function though. The other key works fine

Is a new key the only option?

Car battery is 2-3 years old and in good condition, 26k.

Thanks.

Nick
 
AFAIK the battery has no part to play in the immobiliser circuit.
The immobiliser is actually powered/excited by the loop antenna in the ignition barrel.

Long story short, your key has probably lost its sync with the EWS rolling code somehow, or the immobiliser chip or antenna have broken/ become seperated from the PCB.

I would suggest that you will need someone with an AK90 programmer or similar to see if your key still shows signs of life.
 
I would agree the key has lost its rolling code, the battery in the key only works the keyless entry buttons, the ignition loop reads the code in the chip inside the key. If you can get the key read with an AK90 key programmer or another scanner that can view the keys to see if there is anything wrong with it.
 
Thanks both, I was just reading your other post Colb. I'l have a word with the local indy tomorrow and see if they can do that. Failing that there's a mobile auto electrician which lists key programming. Thanks.
 
srhutch said:
Nice to see you are still around Nick :thumbsup:
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Thanks very much, and you too. Just clocked up 16 years of ownership. I must log on more, though don't usually have much to add, but still a good forum with helpful people. And get out more too! :driving:
 
You can give the resync sequence a try - I had the same no-start issue as well when my battery died (on my aftermarket key which has a cover/replaceable battery).

You may need to double-check this but off the top of my head:

1. Turn the car to ignition (don't start the engine).
2. Wait a few seconds
3. Take the car out quickly
4. Hold down the UNLOCK button on your key
5. With UNLOCK held down, Press LOCK 3 times very deliberately.
6. Release all key buttons - your car should now LOCK itself, then UNLOCK, confirming the resync of that key has completed.
7. If you have another key, repeat from step 4 within the next 30 seconds.
 
Sorry, I meant to say I'd done that, thought I did. Thanks. I've booked into the local indy for Thurs.
 
Update. After a couple of long runs the key is working properly again now so will see how it goes. Thanks for all the input.
 
Piggy backing on this.

My key stopped working and after a year I got fed up and went to a man with a key van who made a new key for me. He told me the original key battery was still working but after trying the pairing combo more times than I can count, it just didn't work.

Then, I tried it with the key near the rear view mirror and it worked, the key then worked properly for about 2 days until it worked intermittently and now it doesn't at all. I put the key on a toothbrush charger over night and it unlocked the car the next day and then stopped working. Surely one unlock isn't enough to drain 12 hours of charging?
 
AC5L4T3R said:
Piggy backing on this.

My key stopped working and after a year I got fed up and went to a man with a key van who made a new key for me. He told me the original key battery was still working but after trying the pairing combo more times than I can count, it just didn't work.

Then, I tried it with the key near the rear view mirror and it worked, the key then worked properly for about 2 days until it worked intermittently and now it doesn't at all. I put the key on a toothbrush charger over night and it unlocked the car the next day and then stopped working. Surely one unlock isn't enough to drain 12 hours of charging?
Click to expand...

So you now have a new key which unlocks and starts the car and an old one which does nothing? When the old one worked, did you use it to drive with for a good while?
 
AC5L4T3R said:
Surely one unlock isn't enough to drain 12 hours of charging?
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If the battery is 17 years old it is possible and very likely that it would only hold charge for a short time. That is very good life from a rechargeable lithium cell.
Not only would its capacity have been reduced, it will now suffer self discharging quite quickly.
Did the van man open the key? There is no way of really assessing the battery condition without cracking the key open, at that point you are 90% of the way to replacing it.

Batteries are about £2 on ebay. I would suggest replacement for the sake of having a spare but that is no good if only one gets used regularly; one will always discharge and fail if not used.
 
The van man made me a new key as I don't have a spare, with one of the newer style fobs. I was meant to go back to him to have it coded but as yet I havent had the time during the week.
 
Jfgoldfish said:
The van man made me a new key as I don't have a spare, with one of the newer style fobs.
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I'm with you.
I am interested how he determined that the old battery is still fine though. Maybe he didn't share that information?

Do you know how much he would charge to code the key? Prices seem to vary wildly.
 
Jfgoldfish said:
Jfgoldfish said:
The van man made me a new key as I don't have a spare, with one of the newer style fobs.
Click to expand...

I'm with you.
I am interested how he determined that the old battery is still fine though. Maybe he didn't share that information?

Do you know how much he would charge to code the key? Prices seem to vary wildly.
Click to expand...

He had a handheld device with a round hole where he put the key and pressed the lock button, you could see the gizmo getting a signal from it. In total, with key and coding it was 150 euros.
 
So I went to the guy on Saturday and he was unable to program my key because the key was completely dead. Not giving a signal to his gizmo.

Then today the key started working again, unlocked and locked the car plenty of times. Tried to pair the new key with the car using the combo, which didn't work.

Now I'm at my wits end as to why I can't get the key to work or why my original key works whenever it feels like. I've ordered a new battery (car battery) as it's almost 3 years old now. Maybe that helps but who knows.
 
When I had my z,I sent my key to"Automobile Locksmith" at Peterborough tel.01733705009.There was a fault on the circuit board apparently but he did it return post.
You will find website on net.Very good service.
 
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