Use an L26 PCM with L32 tune as backup for tuning.

[cemtex]

When I had my last grand prix it was a 97 that I tuned with a DHP. I would keep a PCM as a backup which I did have to use when the computer crashed during a re-flash, bricking the original PCM. It was a one for one swap (L67 from a 97 PCM, with the knock sensor module swapped) and after putting in my saved tune the car had no issue with the swap.

I now have an 07 GT with a L32 and would like to get a HPT for it very soon. I would like to have a backup PCM should I have any sort of computer issues as I did last time. I do not wish to go crazy spending money and L26 grand prix's are extremely common right now in the junk yard. Could that PCM be used as a backup so long as it has been loaded with a tune for an L32? Do I have to stick to a specific year for the PCM like the 97?

 

[BillBoost37]

With HPT the licensing can be interesting the first time you learn about it and should be considered.

If you unlock your vin only, then you can only tune a pcm that has that vin on it when you hook up to it. If you unlock the year, you can overwrite any pcm from that year. So you could overwrite an L26 JY pcm tune with your L32 and specific vin. Just need to ensure you unlock year. HPT is extremely good about how it works and I have never bricked or had any issues writing to a pcm with it. DHP... it helped if you used an offboard to write, the issues it had were other modules on the line would sometimes try to talk to the pcm during a write.

 

[GTPpower]

It's a good idea to pull the radio fuse on 04+ cars before writing them.

 

[cemtex]

Why is that? I currently do not have a stock radio installed and I have unplugged and removed the radio buttons from the steering wheel.

Are there any other major things i should look for when tuning this car? It is drive by wire which I am not a fan of, is there a way to make sure my input is what the throttle will do ASAP?

 

[Fivefingerdeathpunch]

You can't change how fast the throttle opens if that is what you are asking about.

The throttle blade will open as commanded by the pedal, of course things like traction control and torque mngt can cause the throttle to close to maintain traction or prevent you from doing harm to the engine.

As far as I know with 04-07 computer you will want to keep 04-05 and 06-07 stuff together. Flipping flopping a 04 computer into a 07 can make the fuel gauge read backwards for some reason.

Just know that what you want to do will cost you at least 4 credits because as said you have to license your car to get that file. Then you buy another computer you have to license that file so you can edit it, then you could write entire your vehicles file into that computer so you have two computers with the same file.

 

[cemtex]

I just started using the tuner today. It is a lot easier than the DHP for startup and getting an initial read from the PCM. I did not have to pull the radio fuse (I forgot TBH and my radio is not stock) and was able to get a stock scan. HPT has a write up on the situation I posed on the OP so it answers my question.

Are there anymore write-ups for the 04+ cars or should I be good with using information from the 97-03 write ups? It looks fairly similar for a lot of it. Also the tire/wheel ratio calculator says that my current ratio is 3.29, but when I calculate it manually at the drive sprocket ratio I get 2.93 (which is what it should be). Should I just focus on the multiplier and modify manually? My car has 225 50/17 and stock is 225 55/17 (which I have found makes the speedo read higher than my actual speed by about 3%).

 

[BillBoost37]

With HPT you wont need to pull the fuse etc. DHP would have trouble when other things on the wire were trying to communicate as said in my previous post.

 

[jaydubb71]

Yes. The OS will be different (NA tune vs FI tune) but you can flash the settings from your L32 PCM to the L26 PCM and let it eat. JUST BE SURE TO CHECK THE DTC MENU AS THOSE SETTING WONT COPY OVER.