Irritating Problem with tune or ECU or ??? (Loose Temp Gauge Signal)

[mm_n_p]

Sorry about the typo in the title... It is should read (Losing Temp Gauge Signal)

So, everything had been working perfectly until I changed widebands and updated to HPT 4.2 but I'm not sure if that's just coincidence or not.
Vehicle is a 2006 GTO

After putting in the new Innovate LM-2 (which BTW, I hate) I made some minor tweaks to my WOT area VE tables and I thought all was sell. Next time I drive it I realize my temp gauge didnt work so changed my temp sensor, and no change.

At this point I was running short on time (headed to work this morning) so I simply uploaded my tune to the car again and the problem seemed fixed, so I thought... half way to work I noticed my temp gauge had quit working again and car went back to running rich and would not start without peddle to the floor when engine is hot. As soon as I got to work, I uploaded the tune for a third time and again the temp gauge started working and car starts/runs as it should.

This sounds like an ECU issue vs electrical to me since I can refresh the tune for a temporary fix but I'm looking for other suggestions from the HPT board before I start throwing money at it. Due to time constraints, I haven't tried logging the temp sensor signal yet to see if it is there and the ECU just inst processing it correctly but I did just do a Write Entire to see if that does anything but I I'm not too optimistic.

[mm_n_p]

"SOLVED" - So I thought

In the event that somebody may be interested in the status, the problem was solved with a "Write Entire". I hate not knowing what what the problem was but I'm going to chalk it up as corruption in the ECU that may have happened during a sketchy upload attempt.

-Steve

[mm_n_p]

I thought that this was solved, but the issue was only delayed a couple days and it is back to as described above, only now it was warmer out and noticed that the AC dropped out and my engine fans quit working. I did have a few mins to hook my scanner up and noticed that I could control these things from within the scanner and I did have a signal coming from my temp sensor so with that said, I'm leaning towards ECU but am not sure how to explain it.

Any thoughts?
Anybody know which ECU's are interchangeable with an '06 GTO?

[blindsquirrel]

You can use any ECM with the same service number. A matching service number means the hardware inside is compatible with any of the calibrations used with that service number. A matching part number means it's the right service number with the right calibration in it. You only need to bother with a part number if you don't have the ability to reprogram, so just match the service number, flash it with your OS, and you're good to go.

An '06 E40 should be service number 12596679, I think there is only one, but check yours first to be sure. I can almost guarantee that a scrapyard/ebay Grand Prix or Impala 12596679 will be a whole lot cheaper than a GTO 12596679... even though they are exactly identical except for the calibration.

[mm_n_p]

Thank you for the info, all good stuff. I was able to locate one with the correct service number and it will be here tomorrow. Not on 05/06 5.3 impala, envoy, trailblazer etc or their SS counterparts within 200 miles that still has the ECU.

From what I'm reading, it looks like I will have to marry the PIM to the ECU which I believe I will have to find somebody with a Tech2 to do.

[blindsquirrel]

Looks like it. I think you can do it without a Tech2 if you change the BCM (normal security relearn), but not the ECM. The GTO is an odd duck. Everything in the car except for the ECM speaks only UART, ECM speaks only GMLAN, the PIM acts as translator.

https://www.ls1gto.com/forums/showthread.php?t=608178

[mm_n_p]

Well... all is well in Tulsa, OK with the new ECU. I don't really know everything that was wrong with the old ECU but this new seems to have fixed my issues above but also handles Idle Air a lot differently as I had to add right at 30% to it just to keep it from dying when coming to a stop so now it looks like an idle tune makeover at minimum which I could use the practice anyway.

Just curious what it takes for somebody to get their hands on the software and passthrough that GM uses now?

Thank you blindsquirrel for the help.

Steve

[blindsquirrel]

"Uses now" as in up to current year model? MDI2 and GDS.

For everything 2009 (I think, it's somewhere around that) and older:
Chinese Tech2 clone
or
MDI clone (passthrough thing, ~$100)

Tech2Win emulation software and TIS2000 are free from dubious sources, or purchase legit subscriptions from https://www.acdelcotds.com/subscriptions