PCM Flash to Grand-AM Cup PCM

[Stealth97]

I can change the PCM with other systems per our rules. We have remained with this GM PCM because it was working great with the last engine couple of engines. All other people involved are wanting to switch over the a FAST and removing the complexity of the GM PCM.

Why not put that GM ECM on the shelf, buy yourself a 12200411 and pick an OS that works for you and upgrades to COS3 or COS5 or something that fits your needs.

If you aren't limited to PCM's, you can still stick with the GM PCM and remove the unknowns from yours.

[joecar]

What car do your engine/trans/PCM and wire harness come from...?

If you say 1999+ F-body or 1999-2003 Y-Body (can someone please check the year ranges),
then a 0411 PCM would plug in with no harness modification...
A 1997-1998 would need PCM connectors to be re-pinned.

If you do buy a 0411 PCM like Stealth97 suggests, get the seller (any of the forum sponsors are good) to flash it with OS 12212156 from a 2002 F-body with manual trans (as you have a MT)... should be under $100 shipped for a used one.

12212156 offers various options:
- run 12212156 with your tables;
- jump to COS5 with your tables;

And will give you control over timing advance.

(I don't know if your GA PCM fixes advance at 31* via physical means or via OS code patch means).

[joecar]

I'm thinking that a known used PCM will fix your flashing problems (i.e. the GA PCM has been "tampered" with).

[Rusty]

We fixed all mechanical issues that have been causing the strange results. All cylinders are running correct. (No flashing MIL, it was the dead cylinder 8). I have a FAST wide band that should be here tomorrow afternoon. I plan to use the advise that Joecar gave and tune.

As for the PCM. I currently have 2 GM PCM that are labeled Grand-Am and 2 other stock GM PCM (2001 and 2004).
The currently installed GA GM PCM had operating system 09381344 (200 Camaro LS1) which I had problems flashing. I downloaded a stock from http://www.holdencrazy.com/EFILive/stockTunes.php and performed a full reflash operating system 12221588 (2002 Z06). I meant to get the 2001 Z06 but must have clicked wrong.

I currently have no problems flashing or reading. I do wish to have the best performing OS for racing. I plan to start tuning soon. Should I use a different OS? I hope to remove the MAF sensor from closed loop after tuning, if better performance is a results.

The car will run 95% at WOT and the rest of the time between 50% to 100% throttle. Of course, this excludes the full breaking periods.

Attached is a log file with Joecar suggested PIDs. I relearned the CASE and the zeroed out fuel learn tables. Car was not on Dyno. Just parked (1000, 3000, and 4000 RPM), Its amazing that the trim goes to 25% so quickly. I am finally getting O2 readings that make sense!

Thanks for all the help and I appreciate any more advise about operating system selection or tuning! You guys have help a lot!

[joecar]

Stick with whatever works...

[joecar]

Rusty,

You don't use boost or nitrous, so I don't think COS5 will help you...

The other features of COS5 may not help you either:
- open loop AFR table is indexed by MAP vs RPM (instead of ECT vs RPM);
- includes Alpha-N VE table indexed by TP vs RPM (in addition to the normal VE table);
- allows semi-open loop (SOL) which uses STFT to trim to stoich.

I really don't think any of those will help you...

so I suggest to keep developing 12221588 which is working for you.

Cheers
Joe

[joecar]

When you go MAF-less, show us some more logs...

Include these pids:
VSS
RPM
TP
MAP
IAT
ECT
AFR
SPARKADV
KR
IBPW1
IBPW2
DYNAIR
DYNCYLAIR_DMA
LONGFT1 (exclude for OLSD)
LONGFT2 (exclude for OLSD)
HO2S11 (not HO2S12 or HO2S22)
HO2S21 (not HO2S12 or HO2S22)

Keep your channel count to 24 or less for fastest sample rate (important during AutoVE).