Team ZR-1

EPA to prevent people from screwing around with the PCM code and also to protect odimeter, alarm, and code for radio, defined a lock/unlock code software function called data link security.

Review the SAE J2186 standard to see how this security works.

When tool is attached like a programmer, it requests a seed from the PCM. If PCM responds with the seed, the tool then has to return a valid key. If it is wrong key, PCM allows one more try. If it fails 2nd time PCM starts a delay timer and no other seed request is accpeted while in that delay time. Try again and if wrong again, delat time is set longer, etc, thus time consuming but sure someone could write a program on tool side to keep sending key values until it cracks the proper key.

Now if you can get G.Ms code unlocked, you could then replace key with your own key value and lock even G.M out forcing total overwite or flash or worse yet corrupt flash memory and only fix is to replace the PCM since the flash just does not unplug out of PCM.


[quote]Originally posted by 2000 Silver Z:
<strong>There has got to be a way around this "lock" so to speak on our computers. I currently have no use for LS1 edit BUT I feel the pain of some people who's PCM's are locked.

There have got to be some coders on this site who can get around the lock or even crack it, NO code is unbreakable. Time for some reasearch in exactly how the computer operates, if people can re-program DSS sat cards this PCM lock can't be that hard to get around........It just a matter of how much reasearch and time one/team wants to put into it.</strong><hr></blockquote>

Steve in Seattle

1) Tuners typically don't write any code. They don't change a PCM algarthim. They just change tables. How? Because they have money to buy the tools needed. And since we don't, we pay them to use the tools for us.

2) Tuners don't manufacture items by reprograming PCM's. They no create a phyical item, or even a copyright-able original program. They actually "hack" the program owned by GM. EPA rules aside, I'm not sure what GM would say about people messing with the reference tables their program uses if
a) it was A LOT more common (like 50% of cars)
and b) the changes caused a major problem (like PCM freeze up).

Unless tuners mess with, say 100,000 PCMs, then yes, GM doesn't care. If the EPA finds people flashing PCM's for road use (i.e. being installed in a car with a liscence plate), they may make a stink about it though.

Yeah Ed may not want people with similar equipment and goals to beable to read his modifications, but he sure as hell can't copyright GM's algorythm, GM's choice of tables, and his modifications to them. He knows it, and also knows others will look at his mods as a guide if given the chance.

So. Knowledge isn't power, its money. You want some, you gotta pay. <img src="gr_stretch.gif" border="0">

BTW,
Although some people may not agree with the "no viewing" lockout, it is one of those skills that gives a tuner a slight advantage over enthusists and dealerships/garages. Ed's been real good to the LT1 guys with helpful hints and insights so I know he's not "knowledge greedy". I bet if you sent him your PCM he'd flash it back to stock for you. Have you tried talking to him yet?

[ February 09, 2002: Message edited by: Steve in Seattle ]</p>

Palm Beach Z

Yes, I've been in contact with Ed. He said he would flash it back to stock. At this time I'm unwilling to fool with all this and throw over $750 worth of tuning out the window. The car runs great with Ed's programming. I don't have a problem with it at all. I just wanted the ability to tweak the tuning without having to spend close to $250 each time I wanted a little change done. I now have a MAFT and put some MAF ends on the car so will play with it that way to get a little more out of it.
In the future, I'll get a stock PCM and LS1 Edit. At this time I'm happy with what I have. <img src="graemlins/gr_angel.gif" border="0" alt="[angel]" />

Team ZR-1

That's why those tuners lock you out of your own property so you do exactly what your doing.
Not stray to another vendor and pay them big bucks to use a softwate program, select items in a menu, have it change a few values and make that big ptofit.
For their product, they had to steal G.M's copyrighted software, violate federal EPA laws, at least if your using like LS1-edit your not selling G.M code, your making changes to your own PCM for your own personal use.

Having to mail your PCM to some tuner is a joke, not counting your down time, but no matter what, if they do not have yout car, then they are cookie cutting "canned calibrations", guessing and cannot tune as well as you can having the car and knowing how it reacts.
Plus your changes are realtime, not weeks between changes waiting for some so called pro tuner to wiggle a few bits via the same type of program you will use yourself.
The new smog tests are much smarter and those who cannot convert to stock OEM code are going to have their **** in a wringer, rejected and $2,500 EPA fine.

25 states converted to new EPA I/M testing this year, with other states following and those caught with locked code will wish they had a method to swap back to stock code when need be such as smog testing.

These tuners did not work their butts off to come up with what they have. G.M does not give away the source code, they can't.
So people who did like LT1-edit had to do backward engineering, then others if they could rip off their work and then claim they are so smart they write PCM code.
Far from the truth, they are just hacking, peeking/poking and using paying customers to find out if their guesses to a function are right or not.

So to be safe, you control your PCM, cause if you gotta sell the car and it has to be smogged to be sold and your PCM is locked by some moron who wiggles a few bits for $500, you'll wish you could flash your PCM back to stock on your own, rather waiting days or weeks for that $75 fee charged to put something owned by G.M by that tuner taking all profit for a clicking "upload/flash" in a program that you could just as well do for nothing.
I'd demand a non locked version or all your money back and your PCM brought back to the state it was in before they slipped a key in without telling you in writing you were giving them full ownership of your PCM.


[quote]Originally posted by Palm Beach Z:
<strong>Yes, I've been in contact with Ed. He said he would flash it back to stock. At this time I'm unwilling to fool with all this and throw over $750 worth of tuning out the window. The car runs great with Ed's programming. I don't have a problem with it at all. I just wanted the ability to tweak the tuning without having to spend close to $250 each time I wanted a little change done. I now have a MAFT and put some MAF ends on the car so will play with it that way to get a little more out of it.
In the future, I'll get a stock PCM and LS1 Edit. At this time I'm happy with what I have. <img src="graemlins/gr_angel.gif" border="0" alt="[angel]" /> </strong><hr></blockquote>