HP Tuners "Write Entire" to wrong ECM, now can't write anything to it.
 

OK HPT experts, got a dilemma.

I have 2 different E67 ECMs, one is GMPP & the other is 09 CTSV, I can/could write to both of them without issue. But I mistakenly did a "Write Entire" of the GMPP tune to the CTSV ECM (which worked), but now I cannot write anything to the CTSV ECM, says vehicle not recognized, or registered, or something like that.

Am I hosed now & have to use more credits to enable that ECM again? Or is there a way around it?

Thanks

Anyone? Thoughts/suggestions?

When I first made the transition from the LS1 411 ecm to the E38 style over the course of man builds, I found that trying to overwrite a file on any of the E38/E67/E40 ecms bricked it. In the old 411 you could make the file anything you wanted. At least in my experience, once its overwritten its done. Now, I have not ever done anything that had the GMPP ecm. And you can't even change them from manual to auto, etc. It acts like it changes it, but its not actually changing the file. This all started when I had a 6 spd manual LS3, but the E38 was from an auto. Speedo would rear 158mph even sitting still. And it had some odd backfiring on de-acceleration. After a ton of research I basically had to wire in a TCM and use its output for a correct speedo signal. I went to a manual file ecm and everything was perfect. My buddy is a 20 yr tuner. Also, if you have dakota digital gauges using a BIM module, We have found they need to be unplugged from the BIM to be able to access the ecm file.

I take it this is why the ALDL "Y" doesn't work with having the DD BIM connected when the HPT module is connected. Never tried disconnecting the BIM, I just remove the "Y" and connect it directly.

Yes, exactly, thats what I was getting at. Just unplug the gauges. Sorry if I made that confusing.

There are two different versions of the E67 ecm. GM changed them during the 08 model year (I think), so if you're GMPP ecm is an older one, and your tried to write the 09 file onto it, you have corrupted the ecu.

You might get lucky and be able to flash a factory GM program onto it with TIS and a MDI2 (factory GM tools), but I have had mixed success with that. Also, being that it is a GMPP program, you would then have to track that down and write it to the ecm via HPT.

Sorry if thats confusing, I deal with all this stuff a lot, so it makes sense to me. Hahaha

The GMPP ECU's are an odd duck, the only time I messed with one I nearly bricked it.

A few years ago I tried doing nothing other than changing fan activation temps on a GMPP ECU that came with a 480hp GMPP crate engine with EFIlive and nearly bricked the ECU. Should have been a simple operation: read, edit, reflash. But after a couple reflashes the fan activation temps would not actually change, and at one point the flash failed and left the ECU in an unusable state. Left it powered up and kept trying-- took me about an hour to recover it with the original downloaded flash using "flash operating system and calibrations" (the EFIlive equivalent of "write entire" in HPtuners.)

I never got the fan temps changed, and never looked into it any further after that to see if there was a workaround.

As mentioned, there are 2 different versions of the E67 and you may have flashed the incorrect operating system to your other ECU and bricked it, or the "oddball" GMPP OS/flash managed to hose up your non-GMPP E67. If EFIlive or HPtuners can't recover it, you *might* be able to get it back by reflashing with GM TLC / SPS and an appropriate interface (MDI2, Mongoose, etc.)

So, of the people I have spoken to about this, all have said it is done, "bricked" as some call it. SO I have ordered another ECM with the CTS-V stock tune & same VIN.