ECU Swap: ARD Green from unknown year into '97 T-5 Topic is solved

[P80]

Hi All, first-time poster here, writing from Denver with a question about swapping ECU's that I couldn't manage to answer entirely on my own...Thanks in advance for your assistance.

I have a stock '97 850 T-5, VIN YV1LW5720V2293470.

My ECU part number reads: 0 261 203 072
My numbers under the four ECU barcodes: P09125331; c001; 1T26S4585; T96166325
My code on the right side in large type: GC.2

Someone local is selling an ECU with an ARD Green tune.

ECU PN: same as mine (0 261 203 072)
Bar code numbers: P01275389; c001; 1T26S3767; T95109168
Right-side code: 8.2
Seller's (somewhat confusing) notes: "It is tuned for denver elevation. 19lbs for either turbo. Its also tuned for a muffler delete but you could run it with a muffler as well Its a pretty general tune. It is for a glt."

While I have this info from photos, I don't know the year of the vehicle from which this ECU is sourced. Is anyone able to tell from this information if this ECU will work in my Volvo without causing a CEL from fault codes related to EGR or SAS or the like?

Also: the seller says that the ECU comes from a GLT / low pressure turbo car...Am I correct that it's still safe to run in my T5 / HPT?

While I'm at it, here are some more general / random ECU-related questions if anyone would care to comment:

Do these ARD Green tunes offer any performance improvements when simply plugged in without additional mods such as cam timing or wastegate setting adjustments?

What does the red button I've seen on the backside of ARD-tuned ECUs do? In the photos I've seen, it's in the middle of the four bar codes on the ECU.

[bmdubya1198]

The button, I believe, is for a "learning mode." It is for adjusting the ECU for your specific car. That's something I would ask ARD about before messing with it.
Anyway, the GLT tune should work safely with a T5, but you would have to see what turbo the tune was for. Being that it's a green tune, that's a pretty generic tune. It's not how ARD is now where you can select each individual option for a tune. Obviously, this more generic tune will not be as perfect as it could be, but it will work.
If you have a CEL come on depends on if the tune has the SAS or EGR delete. I don't think the '97 T5 (or any turbo) has EGR anyway. If your SAS is in place and working, you have nothing to worry about. It depends on if the ECU is tuned for the SAS delete. If it is, great. If not and it works anyway, great.
19 psi sounds like a lot for any turbo on this engine. I wouldn't run that without the right supporting mods.
Also, being that the tune is from a GLT, that makes it either a '97 or '98. 1996 and older GLTs were not turbo, and '99-'00 ran Motronic 7, which is physically a different ECU, so it won't fit anyway.

[P80]

Many thanks for the reply, bmdubya! Here's where I think all this is landing:

I have a 97 HPT with emission code "2" in the VIN = no EGR and no SAS.

I'm quite confident (despite conflicting info from seller) that the ECU is from a 95 HPT, hence emission code 1 = no SAS either, but it did come coded for EGR equipment.

SO, either the tune included an EGR delete -- and it won't trigger a CEL in my car -- or it's going to trigger a CEL if I run it in my car. (Right?)

HENCE this follow-up question for anyone in-the-know: if I were to put this ECU in my car and take it for a quick test drive, will the ECU trigger a CEL right away if this EGR conflict exists? I have a code reader and I could scan the car after a test drive...but does it take more than just a short drive for an EGR-related code to be triggered?

[rspi]

What kind of car is the ECU out of?

[P80]

RobertDIY! Thanks for responding to my post. I'm not 100% sure...but my best guess is that the ECU came from the factory in a '95 Turbo wagon.

Hope you're feeling better. Take good care!

[rspi]

I asked because the '98 programming is different from the '97 and older programming ECU's. I was told that if you run a '96 ECU in a '98, it can destroy the AC system. I'd probably try to give Lucy a call to figure out what car it will work in.

[bmdubya1198]

Depends where the ECU is originally from. Maybe it was installed in a '95 but came out of a newer car. I know people run Motronic 4.4 as an upgrade on 4.3 cars. But, the only 4.3 cars I think are early '97s, MAYBE late '96s.
If you put in the ECU and it has EGR but your car does not, it will probably throw a code for that. I don't know for sure, but I would assume that's how it will work since it is emissions related.

[P80]

Thanks for the ongoing replies. Based on matching part numbers I've established that both my own ECU and the potential purchase are Motronic 4.3, so I'm good there. (Phew!)

The only real discrepancy that remains for me: the tuned ECU might be coded for EGR equipment and I know my car does not have that equipment.

So at this point my question is: if I install the tuned ECU in my car and drive it, how much driving is required before I can scan it with my code reader to see if the tuned ECU throws an EGR-related CEL? Similar to the elaborate requirements of getting sensors ready for OBDII emissions testing, is there a specific driving regimen required?

[bmdubya1198]

Usually these cars go through their testing cycle in about 40-50 miles. So, assuming this ECU is tuned for EGR, it will likely throw a code within that time frame.