I'm thinking about getting Tunercat, as I already have the cable and I'd like to work on the programming of my A4 Z28. My question is I heard you have a 10% chance of frying your PCM every time you flash it. Does that concensus seem to be true, or did I hear incorrectly?

I have two laptops I could use, however I would probably use the Dell Latitude C810 I have because the batteries work, and I wouldn't have to steal voltage from the car battery for the AC inverter I have to use for my other laptop. The Latitude has a real serial port, so I don't have to use any funky USB -->Serial devices. The Laptop Has Windows 2k Pro and Windows 98 Dual Boot, although if possible I would prefer to flash in DOS.

I read that you should pull the fan relays when you program to ensure the battery doesn't get too low as well, is that a good idea?

I'm sure it wouldn't be a bad idea for me to keep a spare pcm around just in case. What do they go for used?

 

I have flashed mine many times and have never had a problem.
You just have to make sure that everything works before you start writing.

I always read mine first to make sure that the connection is good.
I personally don't remove the fan relay but I feel that it is probably better to do so if you feel your voltage may be questionable. As a matter of fact I will probably start removing it just as a little more protection.

I never leave the car when I'm programming....I don't trust that someone won't trip over the cable or something.

If I had a laptop I would leave it plugged into the ac power supply and make sure that the power saving options were all disabled. (Test this by leaving the Laptop on for a while to ensure that a screen saver doesn't come on and the unit doesn't automatically hibernate).

Obviously all of us are flirting with danger but as long as its a calculated risk I'm willing to take it.
I feel confident that someday the car will bite back but you gotta pay to play....

Best of Luck
Jeff

 

Your are correct, you do have a 1 in 10 chance of frying the PCM when you program. Some people have good luck and never fry a PCM. Others (myself included) have had the PCM fry after only 2 or 3 programmings. That's why I've invested in a pocket programmer and some sockets for my PCM. It's a small price to pay in case the inevitable happens to you (of course, if you are no good at using a soldering gun, you'd be better off paying for someone else to socket your PCM, such as Madwolf or another socketer/programmer).

 

It isn't a TunerCat issue or an LT1 Edit issue. If one is going to perform flash programming of GM PCMs be it with the forementioned tools or even with a GM approved TECH2 download, it the programming operation is halted during its process the PCM flash memory can be damaged and although rare it does occur.

When performing these procedures, its best to be sure that the car battery is fully charged, you have your laptop battery charged up and it is connected to the wall, or if you are like me that does it all on the bench, I have UPS backup power to the PCM power supply and the PC that I am using.

If one corrupts the flash memory all is not lost. People like me for instance and another member code name MadWolf can socket your PCM and reflash your chips for a nominal fee. And if your chips are not usable either one of us can supply fresh new Intel flash memory chips.

 

Yep, I agree with Tom.
I've programmed hundreds of times and only "fried" about 4 or 5 of them.

None of them were due to interrupted programming.

 

theres not a warning with tunercat or LT1edit stating theres a 10% chance of frying the computer when reflashing it. as long as you can read the PCM first and granted both the computer battery and/or the car battery wont lose power... you will be successful 100% of the time. now there are some exceptions like uploading a .lt1 file instead of a .bin file or a corrupted file but you should be ok as long as you are careful. good luck!

 

Maybe I've just been lucky but I've never fried my PCM (LT1edit user). I've probably reflashed mine close to a hundred times already. Listen to the advice given here (make sure your computer/car batteries are in good shape, disable all virus checkers, screensavers, ect., do a read before you program, tell everyone to stay away from your car, don't have your radio blasting while you wait) and you shouldn't ever have a problem. I don't believe the 1 in 10 chance is anything to take serious.

By the way, does it seem that most people who fry their PCM's use tunercat? Not trying to start an argument but to the people who visit this part of the forum everyday, does it seem that more people have problems with tunercat or LT1edit? It always seemed to me that this was more of a tunercat user issue.

 

Unforunately, there are too many factors in my opinion to say it is one thing or the other that interrupts the programming. Of course, we should all take the precautions of battery fully charged, nothing to move the cable, laptop on AC power, and the rest, but I've read more than once about the 1 in 10 chance. When mine fried, it simply established the connection to the PCM, erased the FLASH memory, then never started programming, it just sat at 0% the whole time (this was with the DOS version of Tunercat's programmer). Let it go for 10 minutes before I decided nothing was going to happen. Like I said before, there are those of you that never have a problem. But if this didn't happen very often, no one would need to offer socketing and reflashing for PCMs.

 

FWIW....I erased my flash memory chip about 2 weeks ago. Well, i didnt...by my girlfriends cat was playing with the cord(went to get a beer) and ripped it out while programming the PCM. It was only my 3rd time programming it..Oh well, Madwolf fixed it for me. I sent it to him saturday night and had it back wednesday. Super fast. Anyhow, now I know not to leave the computer at all when its programming the car.

DOOM master...."That's why I've invested in a pocket programmer and some sockets for my PCM."

Where did you get it and how much are they? I think i need one of those as well.

 

I have really bad luck, so if 1 in 10 were true, I KNOW it woulda happened to me. I'm guessing I've flashed my PCM probably 30 times now (LT1_Edit).

Just make sure the power doesn't cut off. I never pull the fan relay, it just kicks on and off when you start programing and when it finishes; if your battery would be getting dangerously low voltage from doing that, I'd be surprised it could even start the car.

With my old battery (which DID suck), I used to pull the harness for my E-water pump, since that runs when the ignition is on. Now that I have a new battery, I don't need to bother.

 

Socket I got from Digikey, they are nice and cheap, if you don't include the stupid $5 handling charge if your order is less than $20 or something like that. The PP2 (pocket programmer 2) I got from xtronics (www.xtronics.com) for $150 + shipping. It will program all PROM and EEPROM/FLASH chips from GM since they started using PCMs to control the engines. Very handy. My friends with GM vehicles (everything from Blazers to Camaros to Cavaliers) have suddenly found the joys of very cheap tuning. I usually just make them give me the cash to buy the def files and then tune their cars whenever they want. I love def files and learning more about programming!

 

Thanks...this is probably going to be my next purchase since I seem to have bad luck. Now all i have to do is learn to solder stuff nice and neat...lol.

 

Cool, thanks for all the comments on it. I would like to hijack my own thread and ask the question, how long does it take to flash the ECM? Is it a few minutes, or like a half hour? I get the impression it takes a while (Getting beer, playing the radio, moving around, etc...)

Thanks again!

 

Just timed it with Tunercat. From the moment you press OK to begin programming till it tells you programming complete - 3 minutes 26 seconds.

OBDII reading is slower than that, but programming is faster.

 

Cool, thanks Madwolf. Hell, I think I can hold my breathe for that long.....