I have a new battery now, still happens. this is an electrical thing, not the throttle body. I've had that, engine will die and then you can usually restart it...this is clearly electrical, like the PCM is rebooting or something. Hopefully the dealer mechanics can figure it out, although I'm wary of them just replacing something on my dime without actually knowing for a fact that it will fix anything.

 

I had this same exact problem a couple months back, even the same Pxxx code (pcm checksum error). Mine turned out to be a bad PCM, but from what I understand theres a few problems that can lead to these symptoms. I also put some new battery connectors in first to no avail (although it needed to be done, theyre way nicer than the stock ones.) I was able to get a PCMforless tuned PCM for cheaper than what the dealer wanted to charge for a OEM one, then I just took it into the dealer for the CASE relearn, done and done. The tuned PCM is amazing, if your PCM turns out to be the problem I'd HIGHLY recommend getting the replacement from PCMforless. It'll take a little while longer to be back in your vehicle but its absolutely worth it in my opinion.

GL

 

I'll look into it, thanks.

 

What is the link for the proper PCMforless company? I tried pcmforless.net (I think that was it) but it was all LT-X V-8 stuff it seemed.

 

PCM Tuning, GM Performance

 

PCMforless is now known as PCMofNC.

Doc posted the link.

 

Thanks...the other place actually forwarded my info to them and they contacted me this morning. I'll see what the dealer finds (going on 3 days now though, so this is a concern) but this sound like a good option if they want to change the PCM.

I'm not sure what this CASE Relearn thing is, however. I assume the car can be driven with just the Security re-learn, but needs the CASE Relearn to run optimally? I wonder what the dealer will charge me to do that if I don't get the PCM from them. There might be a punitive fee lol...

 

Go back and read what Case relearn is on PCMofNC's site, you do not understand it. You only need a case relearn if you buy a new PCM, if you use the loaner program (which 99.5% of people do) there is no case relearn necessary.

If you plan on other mods, you want to do those first, then get the PCM tune set to take advantage of your specific mods (intake, PP TB, CAT back exhaust, larger tires etc...), otherwise you will have to send it back for a re-tune later if you want the maximum potential.

I would not jump to the conclusion that your PCM is bad based upon your described issue. I can think of many other more likely problems.

I have another question for you. Do you have a sunroof and, if so, has your passenger side floor been wet?

 

The dealer just told me that all of their research is saying it's the battery or battery connections. Now, the battery is brand new. The irony is, they want to replace the new terminals with a new stock terminal/harness. I guess the good news is that it failed two or three times while they were moving it, so it should be apparent pretty quickly if nothing has changed once they're done.

 

We already told you that.

Where did you get your "brand new battery?" Auto parts places like to hand you the oldest battery on the shelf (ALWAYS check the Date of Manufacture), and a battery sitting on a shelf for months is not fully charged, you have to charge it. Contrary to popular belief, driving does not charge a discharged battery unless you are on the expressway for 3-4 hours at a time, and that may not be enough for a full charge.