P1572 Immobilizer (not antenna)

[turbomacncheese]

Car was running just fine (well, fine enough to be jumped off the road anyway). Sat for a while, then wouldn't start. Battery failed shortly after. New battery, cranks, no start. P1572 is the only real clue I have. Supporting details: security light on the combo doesn't light up at all ever (I'm certain it did before) and the green ring light around the ignition doesn't light up at all ever (I'm not quite certain that it did before).

I'm stuck on troubleshooting this mess besides cleaning some small amounts of corrosion off the plugs/pins for the immobilizer unit and body integrated unit.

Any ideas?

Edit: Just found this, I guess it's as good a place to start as any -
sec light.png

[Ajzride]

Grounds, grounds, grounds. They play havoc on the immobilized. Clean and tighten all of them.

[turbomacncheese]

While cleaning the terminals, I heard something rattling around so I took it apart. This isn't good.



20240124_164931.jpg

[Ajzride]

Not at all. Is that your immobilizer?

[turbomacncheese]

Not at all. Is that your immobilizer?

It is. I'm trying to get to the bottom of what it treasures to replace it. I'm seeing some people say that it has to be programmed to match the key, and others say that it only passes the rfid info to the ecu, which decides whether it matches.

[Ajzride]

I can tell you from experience that box has to be paired with the key and the ECU. If all 3 don't match you get a no start. What year/engine do you have?

[turbomacncheese]

I can tell you from experience that box has to be paired with the key and the ECU. If all 3 don't match you get a no start. What year/engine do you have?

It's a 2006 wrx engine. I'm asking around to see if any local shops have the subaru select 3. Looks like that's the one needed for this year. There are some dealers in phoenix, but that's an hour away.

[Ajzride]

If you have to replace the ECU/Immob/Key combo let me know. I have been knocking around the idea of pulling mine for an aftermarket ECU, so I could be persuaded to part with mine.

[turbomacncheese]

Thanks. I'm considering that a last resort. I see immobilizers for sale at $20-$40. Some folks have said their dealership could program them, others seem to say their dealership wasn't helpful. Locksmiths(!), small repair shops, and tuners also have helped other people. But if I have to tow my 818, that is going to add a lot of time and expense as I don't own a trailer which will tip the scale a little, soooo, wish me luck.

[Ajzride]

Thanks. I'm considering that a last resort. I see immobilizers for sale at $20-$40. Some folks have said their dealership could program them, others seem to say their dealership wasn't helpful. Locksmiths(!), small repair shops, and tuners also have helped other people. But if I have to tow my 818, that is going to add a lot of time and expense as I don't own a trailer which will tip the scale a little, soooo, wish me luck.

My problem was finding someone who was willing to do it in a kit car. Especially if you have limited documentation on the donor (I bought my kit already half assembled and no documentation on the donor).

[lpmagruder]

My local dealership did it with a little persuasion. I had bought some parts previously and they knew about the build and were excited about it before springing the question, so they already knew me and what I was doing.

I had them make me a spare key and program it too with a backup. I'm forgetting the exact amount but it was $200-$300 for the new key, and programming 2 keys.

They needed the VIN and proof of purchase for the motor and ECU. They did some sort of search on the VIN which I assumed was checking a stolen vehicle database. The actual work took less than 30 mins, the tech plugged some computer thing into it, plugged each key into the ignition, pushed a few buttons, verified it started.

[turbomacncheese]

I have all the paperwork from the auction somewhere. I guess they have to plug in to the OBDII, so no chance if just bringing the parts in?

I should have just gone with an older H6.

[lpmagruder]

They plugged into the OBD2. I towed the car in and they just did it all on the trailer. I think they need there to be a "car" to do this sort of work, pairing a key to a random ECU / immobilizer pair may start to look like a car theft kit for that specific model car.

[turbomacncheese]

Figures. Guess I'll see what I can come up with. Thanks for the info, very much appreciated.