davepl

Other than the price, if you were dead set on running a custom tune but wanted to preserve your warranty (ostensibly) by keeping the factory ECM unmodified, couldn't you load your tune into a part-counter spare, and then swap back the factory one when desired?

That's no different than reflashing the factory tune, other than the flash counts remain at 1.

I feel like this has come up before but "ecm" is too short to search for!

Edit: Fixed title so people don't think there's a magical "Space ECM"

BladeZ06

I believe the deal is that mileage and other parameters are stored in other places than the ECM. One example is the Odometer in the dash. You pull the factory ECM at 10,000 miles the ODO will be synced at 10K. You drive on the spare ECM for 5K and replace the ECM back with the stock one it still shows 10K but the ODO shows 15K.

There might be more to it but that was what I heard.

T/A KID

It can be done... I have customers that had it done.. (I refuse too) bc its ethically not right!

The more we try to "screw" over GM the harder it is for us to mod them.. Right now for 17+ stuff it cost way more tune then anything else and have to send in the ECU/TCM..
probably bc idtiots getting online and saying how they swapped ECUs or how there "handheld **** tune" can't be traced.. thanks to guys like this it's getting very difficult

mdz06vetter

Blade is correct, pieces are stored in many different places other than the ECM; in computer terminology it is called "fail over" and "redundancy" - this was a topic that I queried my local Chebby mechanics about at "shop nite" for my local NCCC meeting. Mechanics also mentioned if folks believe they will NOT be found out are in for a very rude awakening when they go in for warranty work.

Higgs Boson

The ECM is just one small part of a network of interrelated computers that run the whole car.

Either mod your car or leave it alone. Don't try to game the system.

davepl

That makes no sense, and the fact that there are many modules doesn't worry me, nor is it really very relevant to my question. Only one of them controls the engine, it's made to be replaced as a service unit item itself, and can be updated independently of other modules (so far as I'm aware - never seen an update that depended on multiple modules being in sync, anyway). I've paid my dues with Vehicle Spy, ValueCAN, HPTuners, and enough CAN\GMLAN\Module hacking to at least be able to ask the question.

I bet I know what happened. You went into that "C6Z vs C7Z" thread, got all mad, and it hadn't worn off yet.

Sounds like the mechanic merely fostering FUD to me (Fear, Uncertainty, and Doubt). No one has ever claimed GM has access to any post-mortem flash info other than the flash count. That's hardly a rude awakening, and if you did like I asked and used a spare module, even that would remain unchanged. At least I think... and that's sort of the question.

I've got the list of modules right in front of me, it's in the service manuals. Nothing mysterious about it, why does anyone think that it is? I don't care that there are mirror modules and driver's seat modules and PDR modules, etc... just about the ECM. Nor does it worry me that odometer mileage is stored in the gauge cluster instead of the ECM.

Now I'm thinking I might order one and install it with my own tune just to be contrarian! Wonder what they cost? RockAuto has $165, it can't be THAT cheap and simple...

Just to be clear, it still might be a terrible idea, I just would prefer a concrete reason that it's a bad idea, not uncertainty. I do appreciate the advice and feedback, as I'm not a GenV guy, there's lots new in it.

Higgs Boson

you find anger in my post? you are one weird dude. actually, I like the C6Z, I am not a corvette weirdo, I also like hellcats, GT350s, 911's, AMGs, and every other performance oriented car.

if you already know the answer to your question, why post the question? why not simply buy the rock auto ecm and go to town and post results instead? in fact, why don't you just make that your next post and make us all proud instead of posting something else retarded.

Please, don't just tell us all what makes sense. Put your money where your mouth is.

Higgs Boson

short term memory issues maybe?

https://www.corvetteforum.com/forums...or-tuners.html

Blue02ws6

What happens when you blow something up and swap the original pcm in and it has no details of what went wrong? Doesn't it store information, wouldn't they know it wasn't in the car when the malfunction took place? I have no idea, that's why I'm asking.

383vett

In order to get a spare ecm to work, it must be flashed using the owner's vin. The only one that can do this is a GM dealer. Their computers are linked and GM keeps track of ecm flashes for each vin. If the numbers don't add up, the warranty is gone.

HighBeta

Good to know, thanks.

HighBeta

Dave? FYI, the title of the thread still says "space" in my browser.

davepl

Because I figure there's a catch like "Now stop by your friendly Chevy dealer and have them set the VIN on your spare box using a Tech-2", but no one has said that yet. [Edit: Looks like 383vette has suggested it since]

I have several marques in my shop (BMW, Audi, Cadillac, 3 Chevrolet, 3 Pontiac, GMC) and only one is a Corvette, not sure what this has to do with Corvette snobbery

I asked here at the same time I sent an email to HPTuners asking if their software was necessary and sufficient for setting up a blank/new ECM. I haven't heard back, but I've got a hunch GM might need to be involved.

Not sure why I'm getting the pushback, seems like a simple and smart idea for $165 if it works, even though I'm having my doubts... still a reasonable question in my mind.

Yup, looks like editing the title of the original post just does for that post, not the entire thread as I expected. Oh well, Space ECM it is!

NSC5

Dave,

You know space qualified parts are MUCH more expensive than regular consumer stuff

A lot of forum software doesn't let you change a thread title; it seems the only way on most is to get a moderator to use their magical powers. Or you could put something religious and political including a Viper street race in the thread and then the entire thread will probably vanish into thin air.

davepl

Or I could just light a forum fuse in my thread:

"Hmmm... should I trade up from a C6Z to a C7Z, is it better? Because I'm worried the C7Z will overheat, especially if I get the A8, but I'm not sure which transmission is better, and whether or not I should get the Z07 package with it."

NSC5

Well done Dave

Higgs Boson

I am not sure why we are miscommunicating, who said anything about you having "corvette snobbery?" I was responding to your comments insinuating I might be "angry" about something C6 vs C7, which is way off base.

I also don't think you are getting "pushback," no one is telling you not to do it, in fact, I said to hurry up and do it and stop making new threads about it. Just jump! It sounds like you're confident you can do it so what are you waiting for? Paralysis by analysis?

If people say you'll break your leg if you jump off a bridge, that isn't the same thing as saying "don't do it." It just means you have more information before doing whatever you want.

davepl

Seems to me, looking at the thread, that it went like this:

Dave: Can I do X?
Them: Don't even try!
Dave: But would it work?
Them: Don't ask!
Dave: Is it a good idea?
Them: Well, you've already decided, so just do it

There can be no paralysis through analysis when there's been zero analysis. That's the part I was looking for: is it practical, and if not why not. Nothing more.

All I really seemed to get was "It's a bad idea" and when pressed for why, that was greeted with "Well then just do it". Neither really is helpful.

Those aren't direct quotes, that's how it seemed to me, I'm not trying to put words in people's mouths.

For example, if you say "Either mod your car or leave it alone" that tells me zero about the practicality of using a spare ECM. More practical answers would be:

"No, you cannot do it because a Tech-2 must set the VIN" or "Yes, it works fine, did it myself", or "No, because it must be a matched set with the TCM" or anything like that. Concrete stuff. Not feelings.

383vett

All right you two. Go out, drive your cars and enjoy the day.

Higgs Boson

So you ask, is this practical, thread says no, you get mad.

That's how it looks to everyone else. People in general don't like it when you ask for advice then tell them they are wrong/debate them. Just buy the ECM and try it and let us know what you find out. I don't think many people have done that, if any....it's pretty clear all you will find here is anecdotal and it's up to you to provide something empirical. We would all appreciate your experiment and findings.

Anyways, have a nice weekend.