2004 USDM STi Question regarding ecu updates

[imprezarsx]

When the STi was first released there were problems with the maps. If I recal correctly it was excessive det and misfire codes. Upon reflashing to a newer... something.... the problems were cured.

Well I'm working on an 04 STi with the oldest ecu. It has the original A2ZJ500J (AJ241) flash on it.

What flash should I use to upgrade this STi to solve those problems? If that isn't possible with locally available software, what would you recommend?

Thanks a ton for your help,
Dominic

[Tea cups]

The latest one I've seen for your car is A2ZJ710J, which is available in the download section on this site.

[imprezarsx]

ok. Cool.
I wasn't sure if I could flash over an old version if they were different part numbers and all.

I tried that with an 05 and it didn't work. All I got was a flashing cruise, steady cel and practically no throttle response. With or without the checksum fix enabled.

I see a lot of cars lately, how can I help you guys with development?

[Tea cups]

Try to get some of the newer stock roms like the A4TF820F and E (05 wrx) and A4TC401L (03 wrx). Here's links to what is pretty much available in Subaru roms:

http://www.scoobypedia.co.uk/index.php/ ... bilityList

[Freon]

I have been running a ROM based on the 710J (AJ243) on my AJ241 (500J) physical ECU for a week now. It runs fine. I just copied all my maps one at a time from the 500J image I had been working on over to a stock 710J. Took some time since I had to make sure I got them all, but it works fine.

I would say the AJ241/500J, AJ242/700J, and AJ243/710J are all compatible code.

FWIW, the base timing map has almost exactly 1 degree less timing in moderate to high load areas from the 500J to 700J change. I couldn't find any other changes in known maps from XMLwrite.

[juiceman]

Hey guys - I've got a couple of questions about this. I've got an early '04 that had the pinging issue, which was fixed by a Subaru reflash, so I'm assuming I originally had AJ241 on my car and the dealership upgraded it to AJ243.

I've since gone Stage 2 using an AP. The OTS maps brought the detonation back, just like when it was stock. I've had the car protuned, but it still continues to knock.

Does anyone know if this is a code change in the ROM or did Subaru just tweak the maps? I'm assuming that the AP maps were probably based off of AJ241, hence why I'm pinging again.

Freon - I see you're running AJ243 on an AJ241 ECU. I haven't used any of the software from this site yet, I'm curious how hard this would be for a newb to do. I'm a software engineer, so I'm computer savvy (if that helps lol).

Thanks,
J

[Freon]

You just flash the AJ243 ROM onto the ECU. That's it.

I think a protune should have fixed the knock just as well as the Subaru code fix. I'd take the car back to the tuner and ask for it to be fixed. You paid good money to Cobb and the tuner, your car should not knock.

[juiceman]

Thanks for the quick reply. I've been talking to the tuner about the issue and intend on sending them logs, they seem intent to fix it.

Are you sure I would just flash the AJ243 ROM? That won't mess up any of the code/maps that the AP has put on the ECU? I'm just investigating any alternatives to fixing the issue in case the tuner fix doesn't work out.

-J

[gregsachs]

definately _do not_ just flash the aj423 rom to your ecu-that will overwrite your tuner's changes, and quite possibly/likely destroy the ap marriage as well.

[Freon]

juiceman, you really need to start your own thread on this. For now, don't overwrite your Cobb married ECU!

[STIBungy]

I recently had my ecu updated from 241 to 243. With my TGVs removed, it was throwing only 4 codes at version 241. After upgrading to 243, 2 more TGV codes popped up. I just went ahead and removed all the TGV-related codes.