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#99: 02-21-2014, 09:02 AM
09 Key/Fob Upgrade & Programming
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Title: MPG Tuner
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Location: VA
Car: '05 LGT, '12 OBP, '00 G20+T
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05 Legacy key is big and bulky, then you add the fob which is huge too. Luckily subaru switched to a key & fob combo for 09 legacy's that we can use for ourselves.

Information about the new key:
Part Number: 57497AG48A
IC: 1788D-FWBU766

New styled key on the left (from 09 Legacy), old key on right

New styled key on top, it's bigger then the actual key but overall smaller then old key and fob.

Note: It's a good idea to try to program car key to your car before you get the key cut. This way if your car refuses to accept the key, you can return it. Key programming steps can be found at the bottom of this post.

Take the new key apart and you will find the fob, transponder and actual key

You can take the key to the dealer, pay $80 to get your ECU repogramed for it. Or you can salvage one of your current keys and steal the transponder from it. I decided to take the transponder from my valet key.

On a non valet key it's easy to find which side the transponder sits, on valet key it's a guessing game.

Pulled the current transponder out, keep it just in case, put new transponder in (don't mix them up!)

Next take apart the fob part, there will be a white paper with two 8 digit codes. You need the top code to program the key. Take a picture of it/write it down.

Put the key together and go to your car.

Programming the Fob
Programing the fob is annoying and overly difficult on the Legacy. On the 04 Forester (and my Nissan's), you put a car into programming mode, press a key on the key fob and done. But no on the legacy you have to punch in the 8 digit code into the car twice using your lock and unlock button!
  1. Get in the drivers seat and make sure all of the doors are closed
  2. Open and close the driver's door
  3. Insert key into ignition and twist it from LOCK to ON 10 times within 15 seconds, leave the key in ON position.
  4. Open and close the drive's door again, you should hear electronic beep and continues buzzer along with interior light will flash.
  5. You have 45 seconds to enter the 8 digit code in using your lock/unlock door button
  6. Press lock the amount of times you see the first digit for, then pres unlock to move to the next digit. In my example pic code (12345678) you would press lock once, unlock once, lock twice, unlock once, lock 3 times, unlock... until you type all of the digits in.
  7. Once you have entered the 8 digits there will another sound, now you need to reenter the number the same way you did it before.
  8. If the two codes match there should be a beep and doors will lock and unlock
  9. Press lock and unlock on the key fob
  10. Then take your key out of the ignition and wait for relay to click
  11. Open and close the driver's door
  12. Wait a little and the key fob should now be working

More details on the steps an example video can be found here.

Last edited by covertrussian; 08-10-2017 at 05:44 PM..
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