05 LGT Immobilizer issue, key will not program. HELP PLZ

[Nubie]

Hello all.

Last year I spent all summer either out of the country or working from home so my car sat for about 5 months. When I came back the battery was dead. I tried jumping it, and it wouldn’t crank. Bought a new battery and still wouldn’t crank. After the new battery is when I noticed my security light staying on when I inserted my original key.

 

I thought the battery being dead for so long somehow the computer might’ve lost key information so I figured I’d call a locksmith to re-program. Welp no go. Locksmith tried two different routes/tools and car will not accept a reprogram. My buddy is also a locksmith so he decided to give it a go with his tools and nothing. Key will not program. And again this is my original key I have used for almost 10 years. At this point I’m figuring something fried maybe when I tried to jump start it? Another thing to note is if I quickly try multiple times to start it, on about the third or fourth consecutive try it will fire up for about 2 seconds and then immediately shut off and the security light starts blinking.

 

I was searching on the forums here and some people said the ECU is what stores the key programming? Or is it the immobilizer or BCM? What should I try replacing?

 

Any help is appreciated.

[Soobyhobby]

Interesting. I've had cars sit for over a year and fired right up once a battery is installed.

 

Maybe the ignition immobilizer antena somehow got damaged?

 

The immobilizer system consists of key chip, speedo cluster, BIU, ECU, if any of these are changed, it does exactly as your car is doing.

 

The key is read by the BIU, I'm pretty sure. I have reprogrammed immobilizer on many subaru's.

 

Again, I'd guess maybe ignition antenna.

Its the white ring around the ignition where the key goes in.

 

Also check all fuses.

[Pleides]

I had a similar issue with Wilsonville Subaru doing my airbag recall a couple years ago. Neither of my keys would work. They did something with the immobilizer to fix it.

[omnicron]

I bought a SBB Pro and was able to program my own keys for my Subarus and Hondas.

 

it was like $60 at the time. They are a bit more expensive now but still not too bad. If you have to buy a new immobilizer or change a ECU, it will allow me to re-join the keys to the car. Worth the $60.

[Soobyhobby]

I bought a SBB Pro and was able to program my own keys for my Subarus and Hondas.

 

 

 

it was like $60 at the time. They are a bit more expensive now but still not too bad. If you have to buy a new immobilizer or change a ECU, it will allow me to re-join the keys to the car. Worth the $60.

Wow that is crazy cheap!

I bot a XTOOL X100 PAD, which is almost $600CAN. But it does do a lot of other functions.

[omnicron]

I have done some JDM ECU swaps back and forth and been able to join keys to the ECUs no problem. Also change BIUs. I haven't tried much newer than 2009.

[johnlugo115]

Hello i have a manual 2005 legacy gt and im currently having the same problem you hopefully HAD, did you manage to get the car running again?