P59 ls1b cos5 setup help!

[TJWells]

I have a 2002 Z06 originally a 411 pcm. I am switching over to a P59 ECM # 12589162 with OS# 12592618. I need help deciding which os to use. This is an ls7, I'm using a lingenfelter box to convert the crank and cam signals. I would like to use cos5 for nitrous in the future. Also running Flex Fuel. My thoughts were to load cos5 and then copy the tune files from a 2004 z06 file. I have already repinned the ecm connectors. I found a chart to choose the COS# 051200##. Just looking for some direction on a gameplan. Thanks for any help.

[TJWells]

Any Help would be appreciated!

[joecar]

COS5 is available only for OS 12212156 on the 0411 PCM.

[TJWells]

So I can't use my p59 ecm with a cos? my operating system is 12592618 can't I use 051200xx per the tutorial?

[ChipsByAl]

That is correct. You only have access to Custom Operating Systems 01, 02 & 03 with the P59. You could go back to the earlier PCM and run OS 12212156 and COS 05.

Al

[TJWells]

Ok.. so can I run e85 on the 411 pcm? This is a 12:1 motor, it would respond well to e85. If so can you direct me to what I need to to do to add the tables for e85.

[aaronc7]

Also, why the 12592618 OS? Why not the default 04 Corvette OS?

[TJWells]

The p59 ecu I have{that I can use with e85}has that os in it. I have no complaints about using the 04 OS. I just need to know the best choice to get this car running with e85 and nitrous. That may be the 04 OS. I have tried to find a local tuner willing to sell me a base flash to get this car running to bring it to a shop. No one wants to do it. not sure why. So I'll just do it my self. I've done some tuning with my 06 z06.

[aaronc7]

Yeah you'll want to use the 2004 C5 as your base file to make life easiest and keep fuel gauges and everything working as expected.

You'll just need to enable FF on it, but I posted the cax files and a FF enabled 04 C5 tune here to start working with: https://forum.efilive.com/showthread.php?29594-Flex-Fuel-CAX-for-12587603-12592425-and-C5-Corvette-Files

To run the P59, you'll probably need to move the alternator pin in the harness and disable a few of the O2 related codes. Some additional info located here: https://www.corvetteforum.com/forums/c5-tech/4419892-how-to-flex-fuel-on-c5.html

But as already mentioned, there is no COS5 for P59.

You can keep your stock PCM and run COS5, but you won't have a good option to run flex fuel. E85 only tune is no problem, but I don't know how consistent your E content is around there...could be troublesome if it varies a lot and no flex fuel function.

Not sure what the best option is for you in your case, but those are some pros/cons I can think of!

[TJWells]

Now this is the help I needed. Thank You. I already switched pin 52 to 75. switched to green covers on connectors. just gotta do the o2 heater circuits yet. Sounds like I should use the p59 ECM. Is there a COS like 3 maybe? that I can use to control nitrous? with the p59? If not then I guess I could use an aftermarket timing control.

[aaronc7]

I just double checked the COS3 options for that OS and there is nothing for nitrous... only boost. COS5 allows you to tweak timing and fuel (dry shot) based on input pin switch, but yeah only available for 1 or 2 411 OSs.

[TJWells]

Ok, so what's the right thing to do here? Is there a correct ecm to use that I can do a cos with nitrous options and FF? If so which OS do I use? do I use cos5? I have no issues purchasing another ECM. I am a GM parts dept. manager, I can purchase one through my dealership easy enough or used supplier. What would you guys do?

[ChipsByAl]

Another option for the N2O timing concerns is to wire a resistor in place of the stock one. You can use the very low temperature area of the Spark IAT table {B5911} to retard the timing as you deem necessary. Make sure you update the tables {B5943} & {B5944} to "1" for all values at the minimum. I made a quick schematic for an earlier PCM but I'm sure you can use this jpg to get an idea of what to do electrically.
Al24553