Hi all, long story short the main key fob i use to start/lock/unlock my car stopped working yesterday, spare key hasn't worked for probably couple of yrs, anyway went to local car spares shop picked up required replacement batteries for both key fobs and changed them, neither key still works with the button, can unlock/lock doors with keys but car won't start, surely i don't have to reprogram both keys just because I've changed the batteries over🤔 had the same problem with my Golf key fob recently but changed the battery in fob and was fine, no issues, oh cars an 2006 Hawkeye, any ideas chaps plz.

 

Do you know your sigma alarm PIN??

 

Hi Don, i had a quick look thru all the booklets in the car but couldn't see it recorded anywhere, all I've got is the little metal plate on the keyring with a number on which i believe is the number to use for a replacement key, any other car ive had its been a straightforward battery swap in the fob and no hassles 😤

 

I've phoned me nearest main dealer to see if they can get it from their records, their only up the road 5 miles and have details of the car because it went back to them for the airbag recall couple of years ago, just seems weird that both keys don't want to work even with new batteries, unless it's because both keys were dead so one wouldn't sync off the other one, load of hassle if this happens everytime the fob batteries give up😤

 

If you know the PIN then no hassle to reprogram yourself.
If you've been running around with only one working key fob for a couple of years without fixing it then...........................

 

Hopefully get a call back from dealership in the morning about code and be straightforward like you say, i actually only had one key when i bought the car originally and then had to pay out silly money for a second key from main dealer, and then just kept using the same key and spare key sat unused for a few years.

 

Any idea how many digits are in the sigma alarm code? Have found a couple of codes written down on service book but there only 4 digits, main dealer has called back and can't find code apparently, obviously won't give me master code and are saying car will need recovering and taken back to them to diagnose fault and reprogram keys, im beginning to wonder and it might sound daft if my actually car battery has just given up the ghost hence why fobs won't work, but can't see why it should when car started fine the last time i used it before the fob stopped working, haps i'll charge it up first then see if fob or fobs work.

 

4 digits in the PIN

 

Cheers Don, at work at the mo so can't do nowt anyway, but the situation still confuses me lol in theory the car should still start even if you open the car with the key rather then with the fob surely, unless both fobs are dead and need to be reprogrammed or haps the car battery has died as i was wondering.

 

Using the fob should deactivate the alarm and sigma immobiliser circuits and open the doors.
If the alarm is set and you unlock the door with the key, the alarm should go off at which point you can cancel the alarm with the fob or the PIN.
Putting the key in the ignition will then cancel the Subaru ECU immobiliser circuits covered by the RFID chip in the key.
You need to confirm exactly what is or isn't happening.

You also have a security relay in the starter motor circuit controlled by the sigma outputs

 

Being a 2006 I'm not certain what style key/fob is supplied.

IIRC It's a Sigma system but an OE overlay type that upgrades the factory CAT2 to CAT1. So it's not a traditional CAT1 alarm/immobiliser.

If I'm right that means the immobiliser is handled by a small transponder chip inside the key itself which works without the battery (like contactless payment on your credit card). And the alarm is done by the buttons/remote locking. Two separate systems. No fob battery is required for the immobiliser to function (the chip is energised by the aerial coil in the ignition barrel).

If the alarm is not a separate fob and locking buttons are built into the ignition key. Then make sure the transponder chip has not fallen out when charging batteries. They are tiny, and sometimes do not fit securely. It's a little black piece of plastic about 8mm by 3mm in size.

Second do not have two keys on the same ring. The wrong chip can be read and lock out the immobiliser for about 30seconds on each attempt.

Third car battery...make sure it's above 12.4v and it's not gone flat.

 

Hi Don, car won't lock/unlock using either key fob but car will open using the key in the door which unlocks all doors, but then car won't start, the key symbol is flashing on the dash so car battery can't be dead because when I've had a flat battery before the key symbol isn't visible on dash if that makes sense

 

Sounds as if your sigma alarm could have a supply problem (fuse blown) or is dead.
Maybe charge the main battery and check fuses listed above.

 

Cheers for your help, will have a look when i get a day off later in the wk👍

 

I believe the key symbol on the dash should stop flashing when you put your key in the ignition, that shows that the car recognises the RF ID chip in the key. I've also had it where the car battery has enough power to lock and unlock the car but not even get a click from the starter motor when the key is turned, I think the sudden demand for power from the starter motor is enough to open the immobiliser relays so the lights don't even dim on the dashboard.

 

Will check fuse number 3 on instrument panel behind dash as that's for power door lock and remote keyless entry plus will test main car battery and take it from there i think.

 

Basically one key was dead due to a flat battery in that key so the chip looses its code to the car. You've taken the second key appart to change the battery but you've not been quick enough to do so and that has now lost its code.

So in a nutshell you need the 4 digit pin code to deactivate the sigma unit to allow the fuel pump a starter circuits to function.
PM me your reg i'll take a look

 

Old battery was taken out and new one back in fob in a matter of seconds, ain't as tho it was left for ten minutes or summit to be fair, will PM you reg👍

 

Quick update........ Car all sorted, used the code that Rob managed to find out for me and after a fashion got both keys reprogrammed, cheers to all of those who commented and helped me out👍

 

Good news, now record the PIN in a safe place............................

 

First thing i done once i got t car started Don👍

 

Tattoo?