98 Corvette Bench Tune Help

[Tuned55]

I've built another hot rod using a 98 Vette, auto trans. I'd like to learn how to remove the VATS and Emissions. Other than that I left the donor stock. I'd like help going through the process. I'm using the FlashScan V2.

[GMPX]

Have you read the PCM yet?
If yes, then maybe post the file up and someone can sort you out.

[Taz]

Hello Tuned55,

Thanks to the kind folks at EFILive the LS1-A PCM does not require licencing - they are free to tune. In an emissions exempt Hot Rod application, the following should point you in the correct direction.

VATS

G1201 - None
G0801 - No

EGR

B1301 - Disable

Then go the "Engine Diagnostics" folder, "Engine DTC Processing Enablers" subfolder ... set whatever devices are not in use to "Not Reported".


Regards,
Taz

[Tuned55]

have not read it yet. I have it all ready but unsure where to plug it into my V2 FlashScan

[ScarabEpic22]

Need to have a standard OBDII connector wired up to the engine harness to read it. Or build a bench harness that has an OBDII plug, external power, and LS1 PCM connectors.

[Tuned55]

Need to have a standard OBDII connector wired up to the engine harness to read it. Or build a bench harness that has an OBDII plug, external power, and LS1 PCM connectors.

Ok, I have two harness's to use. Where would I find more info for this. Or sould I just plug into one of my cars to do it?

Thanks

[ScarabEpic22]

Not sure exactly what you mean Bruce, you need to have the factory OBDII connector from the donor vehicle hooked into the engine wiring harness correctly. On factory vehicles this is under the dash, not sure where you put it in your swap though. Once it is there (or if it still is), just hook your FlashScan up to it and use the V7.5 software to read the tune out.

[Tuned55]

I was under the impression the ecm's could be flashed out of the vehicle on a bench. I have a couple old take out harness's I could have used for this purpose.

[ScarabEpic22]

Yes that can be done too, refer to the PCM Pinouts pdf. Open V7.5 tune or scan tool, click help->tutorials and select the pinouts or bench harness pdf (forget what its named).

Check out www.eficonnection.com for some more ideas, they have some really nice bench harnesses. Even if just to look at and get a better idea of what you need to do. :D

[Taz]

LS1-A and LS1-B PCM bench top type programming harnesses begin by using the same raw materials (C1 (Blue) connector) - but that is where the similarity ends - these must be wired differently (different pinouts) for LS1-A or LS1-B applications.


Regards,
Taz

[Tuned55]

Making a harness should be easy enough to do with what I have. I'll have to watch the pin call outs for LS1-A and LS1-B

Thanks for all the imput.

[ScarabEpic22]

No prob, if you can its probably easier to leave the PCM in your car and have an OBDII port installed so you can log and make quicker changes. A bench harness is nice for mail order tunes or if you cant communicate with a PCM in a vehicle, but Id never use one for making small adjustments to a tune. Too much work pulling the PCM out of the car and reinstalling it 5 min later, only to repeat in another 15. Lots of time blown doing that. My .02.

[joecar]

Bruce,

Did you get the OBD2 port wired into the harness...?

[Tuned55]

I have the port in my 55 between console and pasenger seat. I haven't wired my truck yet but it will have the OBDII port under the dash. I have another 98 Vette that has a light "Bump" in the front I'll use for my next truck build. It runs but has a leaky radiator. I can use that car to bench tune the PCM for my truck for the time being. Before I pull the PCM from the red vette I'll remoove the VATS and Emissions. I also have a 99 PCM I want to play with for my 55. I'll waite until I have this tunning down.

Thanks for the help Ya'll!!!

[Tuned55]

No prob, if you can its probably easier to leave the PCM in your car and have an OBDII port installed so you can log and make quicker changes. A bench harness is nice for mail order tunes or if you cant communicate with a PCM in a vehicle, but Id never use one for making small adjustments to a tune. Too much work pulling the PCM out of the car and reinstalling it 5 min later, only to repeat in another 15. Lots of time blown doing that. My .02.

Your right on leaving it in the car to tune. I just didn't realize that on this build. My son is building a 240z Datsun with a 98 LS1 and I'll have to tune that the same way or wait until it's done and remove what he wants just before it's fired up for the first time.

Hey I've already learned a ton from everyones imput on here. I plan on staying with this until I consider myself a "Tuner" {:o)