Immobilizer key programming and Cobb Accessport

Is there any reason that I need to unmarry my Cobb AP before taking it to the dealer to get a new immobilizer key programmed?

 

The car is out of factory warranty already and also I don't have that little security number that came with the car.

 

Thoughts?

Bump on this. Taking my car in tomorrow and would like to know as well. Will they need to flash something to my ECU to make the new key work?

Unmarry it just to be safe. I just put a new ECU in my car. You dont want to do that, i wouldnt recommend taking the chance.

I guess I have a similar question, however I don't have an AP. I just have a custom tune...if Subaru needs to program the key, will that mess up everything else on the ECU?

No it wont. They are not reprogramming the ECU just adding a key to it. I never even bothered checking but i'm guessing these cars should have a separate immobilizer ecu unless these cars are way behind the times

Is there any way to just remove it? I'm not really worried about my at being stolen and I need 2 spare keys made. I bought the car used so I have 1 key and none of the key code things.

the immobilizer system relies in the ecm,but it has to match the key code with the bcm, and instrument cluster, there is an rf receiver in the ignition cylinder that reads the code from your key, if the code being read matches the same code stored in the ecm/bcm/IP then the ecm enables the starting and iginition circuits, the issue is that once a new key has been programmed to a car, you are not able to reprogram it to any other car, if you were to replace any of the computers, you would have to buy a brand new key and have it reprogrammed to the car (it runs about 150 dlls parts and labor), i run an automotive shop in nebraska, we buy alot of wrecked cars from auto auctions, i recently bought subaru legacy with flood damage, i replaced ecm/bcm/tcm/instrument cluster (i bought them used form salvage yards at 75 dllrs each) i bought a new key had the dealer cut the combination and program it to the car, the car started right away, if i use my old key, the ingintion opens but the engine wont crank.

the immobilizer system relies in the ecm,but it has to match the key code with the bcm, and instrument cluster, there is an rf receiver in the ignition cylinder that reads the code from your key, if the code being read matches the same code stored in the ecm/bcm/IP then the ecm enables the starting and iginition circuits, the issue is that once a new key has been programmed to a car, you are not able to reprogram it to any other car, if you were to replace any of the computers, you would have to buy a brand new key and have it reprogrammed to the car (it runs about 150 dlls parts and labor), i run an automotive shop in nebraska, we buy alot of wrecked cars from auto auctions, i recently bought subaru legacy with flood damage, i replaced ecm/bcm/tcm/instrument cluster (i bought them used form salvage yards at 75 dllrs each) i bought a new key had the dealer cut the combination and program it to the car, the car started right away, if i use my old key, the ingintion opens but the engine wont crank.

I believe this is inaccurate. It's not the keys that get programmed, it's the car. If you had to replace the ECU, the old keys can be reused as long as the car is programmed to accept them. When the dealer programs the car, you must give them all the keys you want to use (up to 4 I believe).

Evan you should probably do a research before you post something you are not sure about, guessing is not the best idea, when you do that instead of helping people you confuse them more. thanks for the reply though.

Evan you should probably do a research before you post something you are not sure about, guessing is not the best idea, when you do that instead of helping people you confuse them more. thanks for the reply though.

 

I agree completely. Welcome to the board, but don't be so quick to jump to conclusions. Your description is not correct.

 

The immobilizer is a solid-state, ceramic repeater. There is a transceiver in the column, and a signal is sent to the key. The returned signal is what matters. The ECU, in programming mode, sends a signal to the key, then gets the return signal. The return is unique to the chip. The ECU records it, and the immobilizer is now keyed to the ECU. The use of any other key will result in an incorrect signal return, and the car will not start.

 

Only the remote fob is programmed, but that has nothing to do with the immobilizer. You can start a car with a non-working remote. You can't start a car with a non-coded immobilizer.

Evan you should probably do a research before you post something you are not sure about, guessing is not the best idea, when you do that instead of helping people you confuse them more. thanks for the reply though.

 

Thanks for the advice, we should all try to follow it.

 

Here is a portion of my research from the 2005 Legacy Owner's Manual (emphasis mine):

Your key number plate and security ID plate will be required if you ever need a replacement key made. Any new key must be registered for use with your vehicle’s immobilizer system before it can be used. Up to four keys can be registered for use with one vehicle. For security, all the keys registered with your vehicle’s immobilizer system will have their ID codes erased and re-registered when a new key is made. Therefore, all of your vehicle’s keys must be presented when a new key is registered. Any key that is not re-registered when a new key is made cannot be used after the other keys are re-registered. For information on replacement keys and on the registration of keys with your immobilizer system, contact your SUBARU dealer.

 

I'm not sure which part of my statement you believe to be incorrect, perhaps you can clarify if you still feel I am wrong in stating that old keys can be reused. It's not that complicated, the programming procedure simply tells the car what keys are allowed to start the engine. The keys themselves are not programmed.

 

A situation I can think of where a key gets programmed is when purchasing an aftermarket key such as an ILCO key. An ACE hardware near me quoted me $60 for one and said I just need to have a working key for them to match. I can only conclude that they are digitally duplicating my key since they said my car does not need to be present. I'm assuming the keys are using passive RFID. In this situation, the car wouldn't know the difference between the two keys, hence, no need to reprogram the immobilizer system.

the reason for a new key is because they have no way to retrieve the specific rf id code on a used key, that number is printed on the label of the original packaging of a new key, when you buy a car they don't tell you, "oh, in case you replace your ecm with a performance one, here is the rf id code for ur key", I'm guessing you count with better equipment than the techs have at the subaru dealership.

when you buy a car they don't tell you, "oh, in case you replace your ecm with a performance one, here is the rf id code for ur key"

 

Yes they do. They give it to you on an engraved tag with the new keys. They went to great lengths to make sure I knew not to lose them when taking delivery of the car. There's even a specific place for you to record them on the MySubaru site:

 

Immobilizer Code

The immobilizer system is designed to prevent an unauthorized person from starting your engine. Only keys registered with your vehicle's immobilizer system can be used to operate the vehicle. Even if an unregistered key fits into the ignition switch and can be turned to the "START" position, the engine will automatically stop after several seconds.

Each immobilizer key contains a transponder in which the key's ID code is stored. When a key is inserted into the ignition switch and turned to the "ON" position, the transponder transmits the key's ID code to the immobilizer system's receiver. If the transmitter ID code matches the ID code registered in the immobilizer system, the system allows the engine to be started. Since the ID code is transmitted and acted upon almost instantly, the immobilizer system does not impede normal starting of the engine.

The security ID is stamped on the metal plate attached to the key set. Write down the security ID and keep it in a safe place other than the vehicle. This number is needed to make a replacement key if you lose your key or lock it inside the vehicle. This number is also needed for replacement or repair of the engine control unit, integrated unit and combination meter.

Not true. Even when you buy the car new there isn't an RFID tag for each key. You have the option of either typing in RFIDs or having the ECU read them.

 

EDIT: Car comes with 3 keys and two tags...the code on each tag is a different number of characters. How this equates to 3 unique RFIDs is beyond me.

the reason for a new key is because they have no way to retrieve the specific rf id code on a used key, that number is printed on the label of the original packaging of a new key, when you buy a car they don't tell you, "oh, in case you replace your ecm with a performance one, here is the rf id code for ur key", I'm guessing you count with better equipment than the techs have at the subaru dealership.

 

You CANNOT change the immobilizer signal. The chip within the key is NOT changed during programming.

 

All you can do is program the ECU to accept the new key.

Did you just say a new key??

Okay, I took my keys into the dealer with the Cobb AP still installed and I didn't have a problem at all.

 

The immobilizer in the car is programmed to accept the signal emitted by the key. The signal from the key does not change. I didn't know the code to my original key but the dealer didn't care as they were able to find it.

Not sure if I should even ask on this threat but does anyone know if I can just buy a blank transponder from say this website http://www.autotransponder.com/2006_subaru_legacy_key_blank_transponder_chip

 

and just take it into Subaru and have them program for me @ $50? Are there even cheaper ways to do this? All I want is a 2nd set of keys since when I bought it from the previous owner, he only had 1...

 

Thanks guys.