Well, once again, I lost my PCM again using TunerCat. I was again trying the windows based version. I started with trying reads. I must have made 10 to 15 attempts at reads and all ended with the infamous "incorrect message sent" error. That was trying both the old and new versions of Cat. Then, I disconnected everything and rebooted and retried again. All of a sudden, it started reading. I made 3 successful attempts reading using the windows version. I then immediatly went for a program. I didn't disconnect or touch anything between my good read attempts and my program attempt. It estabilished communication with the PCM, erased my flash, started programming, then immediatly errored for incorrect message sent. I had my one retry, but it errored again leaving me with a dead PCM yet again. This is what I have confirmed. It is NOT a voltage issue and pulling fan relays or ABS relay will not work. I tried that during my unsuccessful read attemps and none of that did the trick. Even after hooking up jumpers and getting well above 12 volts, it still didn't read. This is too weird considering the success I had the night before and again, I am doing everything exactly the same way. I have already contacted Tunercat and am waiting for a reply from them and a course of action. And yes blackcamaro, when this PCM goes out, I will send AKMcables my current program to put back in it when it's repaired so I can at least put that back in my car and be back to normal since next time around I will be trying on my backup PCM. I just cant use that one now because it doesn't have a program that will work with my current mods. Back to the drawing board and I'll keep everyone posted on whats going on. For now though, the Camaro sits cold and dead in my garage.

Ken R. 95Z

 

Unfortunately, this is a very common thing. Anytime you do a program, you have a 1 in 10 chance of getting an error and frying your PCM. There really is no solution to this problem short of buying a Tech2 or Tech1 tool to do your programming (an expensive solution at best). But, if you can do it yourself or have someone do it for you, desolder you flash chips and get a Pocket Programmer 2 for $150. Then, when you fry your PCM, you can simply pull out your PCM, open it, pop out the flash chips, reprogram the hex file into the chips, and pop them back in. This is about the only good solution for the problem. I can't find the PP2 website, so someone else post it if you have it please.

 

Thanks for the info. Problem is that for me for some reason, i've only had a 2 in 2 chance of frying the PCM. I'd be more then happy to get a 1 in 10 chance in that case. Yes, i'd like to reprogram the chips in the PCM myself. I'm perfectly capable myself. So if someone here knows where I can get the programmer to do that, please let me know. Doom, where would I find the Hex to do that cause I may know someone that already has a burner. Thanks.

Ken R. 95Z

 

If you desolder the chips and put in a ZIF socket then you can swap out the chips easily if they fry. I have an emp10 I use for programming (from needhams).

As for 1 in 10 chance - it should be much better than that if everything is correct. I have over 400 flash files on my laptop (each representing another flash) - 100 on my car alone, and no fried pcm's.

If you have a MSD or other ignition box remove that. If you still have problems I would re-run the signal and ground wire for data transfer from the pcm pin to the aldl port (and probably use a shielded wire). If you still have problems then put together a benchtop programmer - if there are still issues then it is either your cable, pcm, or laptop.


Chris

 

hence why i love the 93's, removable chips. hehe

for programming stuff, visit thirdgen.org, they have a nice board there regarding chip burning, etc.

 

good god...you have to be joking!

3 rules to programming..learn them, live by them:
1. ALWAYS run CATS it in DOS
2. ALWAYS read the pcm first..1 is all you need.
3. ALWAYS make sure you have power save options off or hit space bar periodically thru the process.

 

Hmm...I've been using the windows flash program and haven't had a problem and I've probably flashed about 100 files.

 

Turbo Z, I followed your 3 rules exactly, but I still lost the PCM. Dan K, since your using the windows version, can I ask what type of computer you have (processor, RAM, windows version ect...). Just curious. Also, where did you get your cable to hook up to your computer? Thanks.

Ken R. 95Z

 

Chris, why would I remove my MSD to program? Or i'm assuming you might mean kill the power to it or something. I just don't understand why you would do that when your not programming while the car is running? Thanks.

Ken R 95Z

 

I'm wondering if this all has one simple fix that we're not thinking of...

Anyway, what is involved in getting the "benchtop" programmer. Does that mean you have to physically remove the PCM from the car and buy a different harness? When Andrew reburns the PCM... what exactly does he do? I'd love for him to view these boards and help us out since he seems to know more about it than we do .

 

You remove the MSD (unhook it - at least from power) since it has been known to cause interference. Probably a longshot, but can onlly help.


A benchtop programmer requires removing your pcm - it hooks up the data and signal ground wire, as well as a few required grounds and power sources - you can then program directly.


Andrew's repair consists of de-soldering the chip, soldering in a ZIF socket, and putting in a new chip. With a ZIF socket you can then change chips out without and soldering.


Chris

 

Computer is a Compaq Presario 700Z laptop, AMD Athlon 1000, 256 MB RAM, windows XP, and the cable's from Andrew.

When we were initially trying to program cars (I have 5 friends cars that I do), we were using the DOS flash program on a different computer and kept getting errors trying to read. After probably 25 tries I finally got 1 good read and thought no way was I even going to try this. Downloaded the windows flash on my computer and I've never had a problem.

 

I know it's already been said, but I was suppose to add after the desoldering part that you need to socket the PCM so you can just pull the chips out when they get corrupted. As for the hex file, I'm know Andrew has one for every year, as well as the guys over at PCMforless.com I'm sure. I doubt either would have a problem sending you the stock hex for your car. Sometimes I type too fast for myself and skip what I was thinking. Anyways, almost any EEPROM programmer will work for the 40 pin flash chips in our PCMs, but to make sure check if it will work on AN28F512 chip (sometimes abbreviated AN28F). Chris B mentioned the EMP10, I've mentioned the Pocket Programmer 2, there are a ton of others out there of varying price. As for the simple fix, I've never seen one aside from socketing the PCM so you can easily remove the chips and reprogram them. The 1 in 10 chance is something I read as I was going over technical info on the LT1 PCM and I'm pretty sure its accurate. Remember, you might not have any problems, but as you can see a number of other people (including myself), have had these problems multiple times. Your one of the lucky ones, fortunately for you! Some people have good luck with the WIN FLASH program (mostly those with WIN NT based platforms like NT or 2000) while others have luck with the DOS FLASH program (mostly those who use WIN9x platforms like 95 or 98). It would have been nice for GM to have built in an automatic flash dump to erase the PCM and make it able to be reprogrammed from the ALDL port, but I doubt they intended us to be playing with the PCM like this. Just invest in an EEPROM programmer, have Andrew or someone else socket your PCM, and then you can program away with no worries about fried PCMs.

 

I know the feeling, I've been there.

The problem I had with programming was that for some reason, I could program my car with no problems, but I burned my brothers PCM twice. I found out that I could plug my laptop up to a dropcord, and have no problems reading or programming with tunercat. Eventhough I had all my powersaving modes off, It still didn't matter, I had to have a laptop running with an external power source instead of it's battery.

This is prob. not your problem, but just for saftey, try it. It d&ymn sure can't hurt anything.

Good luck

And I'd love to have some of those easy to remove chips that you all are talking about.

D Moss

 

if you guys get security codes..what i have done is just keep pulling the PCM fuse to reset it. sometimes i have continual problems with errors until i reset the computer.

only other solution i can offer is get a different computer. my desktop i use at school(on now) has NEVER messed up. but an old laptop i use does all the time or did but fixed now with the updated version of CATS. a friend of mine tried to use his brand new DELL laptop...never could get it to work. another friend tried his new sony laptop...said my cable was bad and wouldnt work. so you just need to get the right equipment it seems.