1999 C5 P59 PCM Help!

[kingpin4329]

Super new guy here and could definitely use some assistance from this crowd if any kind soul is willing to lend their expertise! I've got 560hrs logged so far into this 1999 C5 project that I bought bone stock 3yrs ago and I'm ALMOST done....but I definitely am at a point where I need to ask for help and I'm lightyears away from what my budget originally was (typical i know ).

So here's what's going on - I just moved over to a P59 pcm from a P01 and I have (I believe) pinned it properly for wideband data to come through the EGR channel and ethanol sensor data to come through the previously unpinned ethanol sensor channel. While i'm not currently seeing any data over these channels in HPTuners - this could very well be a lack of HPtuner knowledge or a maybe even a wiring issue - both of which I can probably figure out myself (not so worried about this).

What I can't figure out however is if the OS installed on this PCM is actually capable of producing all the necessary ethanol tables i'll need for tuning or if it has the EGR functions enabled that will allow it to communicate with a wideband. I've seen so much information online at this point that I'm more confused than when I started and I have absolutely no idea what to look for. What I do know however is that I don't want to buy yet another 100$ worth of credits just to find out that the OS needs to be changed or something where i'm stuck with the need to continue buying credits until i find the right combo.

I'm extremely new to tuning and will absolutely be seeking professional help when it comes time to get this thing back on the road. If any of you out there could possibly be so kind as to take a look at this setup and let me know if I'm good to move forward on this PCM - i'd be forever grateful. For anyone else that has additional comments or info to add - I'll take everything and anything you can teach me!

The attached tune file below is the "stock" tune file the PCM came. If any other info is needed, just let me know and I can get it for you.

Base Tune File.hpt

For anyone interested, here are the relevant PCM harness/pin modifications that were made:
(C1 Blue) Pin 56 - Ethanol Sensor data
(C1 Blue) Pin 55 - Wideband Analog +
(C1 Blue) Pin 41 - Wideband Analog -
(C1 Blue) Pin 67 - Ground
(C1 Blue) Pin 64 - Ground


Lastly, for sh!ts and giggles, heres some links to my documentation on the build:

Electrical Diagram:
https://kdstudiosnet-my.sharepoint.c...Z-n6A?e=WKGFjJ

Parts List:
https://kdstudiosnet-my.sharepoint.c...SV4yg?e=KsVtzI

Labor/Parts Worksheet:
https://kdstudiosnet-my.sharepoint.c...yno2w?e=jpL3uP

PXL_20250123_023616237.jpg

PXL_20250118_165904381.jpg

The "jist" of the engine build:
LS1 Block
317 Ported and Polished Heads
BTR LS7 Lifters
890cc Siemen Deka Injectors
450lph Fuel Pump
A&A Supercharger V3 ti Kit w/ 3.47" Pulley
8 Rib Belt Configuration
TSP Boost Cam (227/234 114LSA)
Long Tube Headers (1 3/4" ID)

[gametech]

The 12587603 OS is the best one you could have picked for this. There are several flex enabled files posted on the board for that OS. Some for 4l60 and some for 4l80. Just segment swap whatever you need. Also, I just looked and your EGR is NOT enabled yet.

[kingpin4329]

Thank you for that clarification gametech! Knowing that the OS is a solid option for what i'm doing is great news and makes me feel confident about paying for the credits. This c5 has the m6 (6-speed) transmission but i'll start searching and see what I can find around here.

Dhoagland was kind enough to take a gander at things as well. He was able to enable EGR using some older HPTuner software and thinks the flex fuel tables i need are all there. Confidence is rising!

[gametech]

Just be aware that you will have to change from a P/N starter lockout to a clutch lockout, and probably turn off a ton of transmission codes, as well as possibly disabling all the trans torque management stuff. I don't know if any of this will be able to be segment swapped, or if you will just have to manually make the changes, because I don't believe that OS was used on any factory m6 vehicles.

edit-- I believe as long as you stay under 15psi you should be ok, but if you convert to the 3barsd OS, it may undo your EGR input. I do not have any sort of list of which operating systems this applies to, but some 3barsd definitely won't keep the EGR input.

[kingpin4329]

gametech - The OS was supposedly modified from the seller (ebay) to work for the manual trans (m6 as mentioned) as well as provide ethanol tables. Trusting that this was all done correctly is partially why i'm coming here and hoping some of you guys can take a peak to make sure things were done correctly. I just found out that I may have accidentally posted the wrong "tune" file so i've edited my original post to include the file I just pulled down from the VCM editor. Could you take a peak and see if you're seeing the same issues?

[kingpin4329]

Can anyone assist with turning on EGR for this tune? I've been toying with it tonight and finally purchased the credits for this PCM. Would be great to see if all the wiring I did works! haha

P59 ECU_Modified.hpt

[gametech]

This should have the EGR flag enabled. The airflow and spark correction tables for EGR were already zeroed.

[kingpin4329]

this should have the egr flag enabled. The airflow and spark correction tables for egr were already zeroed.

thank you!

[Klay]

First off am I crazy or did you post this on corvette forum last year under a similar username?

Second have you contacted aaronc7 over on that forum he helped me do a p59 swap w/e85 and get the egr to read my wideband.

[kingpin4329]

First off am I crazy or did you post this on corvette forum last year under a similar username?

Second have you contacted aaronc7 over on that forum he helped me do a p59 swap w/e85 and get the egr to read my wideband.

Haha! Nope that wasn't me! THis is actually the first time i've created any posts on any forums about this build. I've been selfishly sucking down all the info ya'll have left without providing anything in return

I'll have some good articles to put together for the corvette crowd once i'm done. I've documented the snot out of this thing for that reason in particular. I'll definitely have to go find Aaron and see what he can do to help!

[qwikv6]

not sure where you are on this as its been awhile but i converted my 98 c5 auto to a p59 and a t56 6 speed with flex fuel sensor and a properly working fuel gauge. i did not howeveer log wideband through egr as i have the external input for my hptuners(i forget what theyre caling it now). Either way I've gone from ls1/auto to ls3/6speed back to ls1/6speed so I repinned my orignal 98 harness and made the necesary changes for the manual transmission swap, and recently used the harness that came with the ls1 from a 2000 c5 auto and pinned it for the manual trans and p59. dont ask why i went back to ls1 from ls3 its an expensive story. I also chose to use another piece of software thats out there to enable the flex fuel and it worked perfectly. The other software is open source and you just need the patches to fix the flex fuel. pm me if you need more info.

[kingpin4329]

You couldn't have popped up at a better time. I was just looking back at this post, hoping that someone had added some info here as I'm just now getting around to tuning this thing. I'll PM you now and maybe you can help me get the flex fuel components up and going! Thanks brother!

[bk2life]

You couldn't

where are you in phx? we have several tuners all over here