locking and unlocking a PCM HP tune
Thread Starter
Joined: Apr 2004
Posts: 1,378
Likes: 14
From: Atlanta, GA Ft. Walton Beach, FL
locking and unlocking a PCM HP tune is it possiable that a tuner can lock a tune meaning it is pasword protected and w/out the password PCM can't be retuned?
if yes can PCM even be scanned w/ HP to log stuff?
if yes to initial ? then what is the soloution for future tunes (if password is unavailable)? replaceing the PCM?
if yes can PCM even be scanned w/ HP to log stuff?
if yes to initial ? then what is the soloution for future tunes (if password is unavailable)? replaceing the PCM?
Thread Starter
Joined: Apr 2004
Posts: 1,378
Likes: 14
From: Atlanta, GA Ft. Walton Beach, FL
price of new PCM so even a well respected tuner expert like you'reself wold still have to replace a PCM in this situation?
I have my susupions about the PCM being flautly at WOT causeing the ping.
do you know how much I would have to give for a new PCM?
I know the price of the big stuff.
Thanks for the feedback
I have my susupions about the PCM being flautly at WOT causeing the ping.
do you know how much I would have to give for a new PCM?
I know the price of the big stuff.
Thanks for the feedback
If your PCM is faulty, you would have more problems than just knocking at high rpms.
Who did your tune? Are you sure its locked? Why not go back to them and request them to check your tune and tell them what issues your having.
Have you checked everything else that could be causing the knock? Plugs, Wires, fuel, etc?
Who did your tune? Are you sure its locked? Why not go back to them and request them to check your tune and tell them what issues your having.
Have you checked everything else that could be causing the knock? Plugs, Wires, fuel, etc?
Here is the lowdown: GM 'locks' their PCM's when they program them. However the software companies that sell tuning software know the 'keys' to unlock the PCM based on the key values that GM uses. When a 'tuner' locks your computer they are 'rekeying' the lock to use a value that is different than what GM used.
The computer will behave just like any other computer as far as scanning, etc. but it can not be read or written to unless you know the key value the other tuner has installed in place of the GM value.
Unless another tuner has knowledge of how to unlock the PCM essentially the PCM is useless except to the original tuner. However I do offer an unlocking service for $75 to unlock most LSX PCM's.
The computer will behave just like any other computer as far as scanning, etc. but it can not be read or written to unless you know the key value the other tuner has installed in place of the GM value.
Unless another tuner has knowledge of how to unlock the PCM essentially the PCM is useless except to the original tuner. However I do offer an unlocking service for $75 to unlock most LSX PCM's.
Thread Starter
Joined: Apr 2004
Posts: 1,378
Likes: 14
From: Atlanta, GA Ft. Walton Beach, FL
curious I've read here a little about this fasanating (to me) subject PCM (software controlling hardware).
? if someone connects HP just to scan will they also be able to know if it's locked or not?
Thanks for you're expert feedback
? if someone connects HP just to scan will they also be able to know if it's locked or not?
Thanks for you're expert feedback
You can USUALLY safely assume that if you get an invalid authorization code error upon reading the pcm that its locked...there are a few rare exceptions but thats the general rule of thumb.
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Thread Starter
Joined: Apr 2004
Posts: 1,378
Likes: 14
From: Atlanta, GA Ft. Walton Beach, FL
I'm still confussed.
you say The computer will behave just like any other computer as far as scanning, etc.
if the PCM is logged on to w/ another version of HP (other than orginal tune) just to scan ?1.will be able to scan?
?2. will see if it's locked or not?
thanks
you say The computer will behave just like any other computer as far as scanning, etc.
if the PCM is logged on to w/ another version of HP (other than orginal tune) just to scan ?1.will be able to scan?
?2. will see if it's locked or not?
thanks
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Verdad Gallardo Thread Starter
Joined: Apr 2004
Posts: 1,378
Likes: 14
From: Atlanta, GA Ft. Walton Beach, FL
Pm If your PCM is faulty, you would have more problems than just knocking at high rpms.
Who did your tune? Are you sure its locked? Why not go back to them and request them to check your tune and tell them what issues your having.
Have you checked everything else that could be causing the knock? Plugs, Wires, fuel, etc?
Who did your tune? Are you sure its locked? Why not go back to them and request them to check your tune and tell them what issues your having.
Have you checked everything else that could be causing the knock? Plugs, Wires, fuel, etc?
I will PM you the details of my tuning experience.
Please read Geoff's post, he articulated it perfectly.
https://ls1tech.com/forums/12512914-post5.html
https://ls1tech.com/forums/12512914-post5.html
To put this into simpler terms...If you have a PC that you can go on and look at the internet it is similar to you scanning your PCM. If you go to install a program on your PC, that is similar to you 'reading' or 'writing' to your PCM. If I 'lock' your PC you might still be able to go on the internet and look around, but you can't remove or install software on it. Does that make sense?
Thread Starter
Joined: Apr 2004
Posts: 1,378
Likes: 14
From: Atlanta, GA Ft. Walton Beach, FL
Pcm If you plug a scanner into ANY PCM you will get whatever data the PCM normally puts out. The PCM doesn't tell you it is locked however. The only way to see if it is locked is if you try to read the flash or write to the flash (which is entirely different than looking at a data stream that the PCM puts out...).
To put this into simpler terms...If you have a PC that you can go on and look at the internet it is similar to you scanning your PCM. If you go to install a program on your PC, that is similar to you 'reading' or 'writing' to your PCM. If I 'lock' your PC you might still be able to go on the internet and look around, but you can't remove or install software on it. Does that make sense?
To put this into simpler terms...If you have a PC that you can go on and look at the internet it is similar to you scanning your PCM. If you go to install a program on your PC, that is similar to you 'reading' or 'writing' to your PCM. If I 'lock' your PC you might still be able to go on the internet and look around, but you can't remove or install software on it. Does that make sense?
I'll PM you w/ details of my next few mods I've planned.
Aaaaahh ok. I remember you. It didn't hit me at first. Hope all is well.
Your ping @ WOT is probably in the tune, not the PCM's fault for being faulty. I'm sure somebody just threw 28* of timing in there, set the PE at a generic command and let it ride. I'd be willing to bet the MAF has never been scaled, or VE's ever touched on that car. That has to be done FIRST, before anything else.
Your ping @ WOT is probably in the tune, not the PCM's fault for being faulty. I'm sure somebody just threw 28* of timing in there, set the PE at a generic command and let it ride. I'd be willing to bet the MAF has never been scaled, or VE's ever touched on that car. That has to be done FIRST, before anything else.
FWIW, I don't know how the other guys are unlocking but...
I just unlocked one. My process involved removing the SMT Flash chip in the PCM though; I'm not sure what approach other tuners are using.
I just unlocked one. My process involved removing the SMT Flash chip in the PCM though; I'm not sure what approach other tuners are using.
Teching In
Joined: May 2010
Posts: 18
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Care to PM me the details? I have a few eeprom/flash readers and might be able to pull it off....
Registered User
Joined: Mar 2016
Posts: 1
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From: Kellogg Idaho
my PCM is locked Here is the lowdown: GM 'locks' their PCM's when they program them. However the software companies that sell tuning software know the 'keys' to unlock the PCM based on the key values that GM uses. When a 'tuner' locks your computer they are 'rekeying' the lock to use a value that is different than what GM used.
The computer will behave just like any other computer as far as scanning, etc. but it can not be read or written to unless you know the key value the other tuner has installed in place of the GM value.
Unless another tuner has knowledge of how to unlock the PCM essentially the PCM is useless except to the original tuner. However I do offer an unlocking service for $75 to unlock most LSX PCM's.
The computer will behave just like any other computer as far as scanning, etc. but it can not be read or written to unless you know the key value the other tuner has installed in place of the GM value.
Unless another tuner has knowledge of how to unlock the PCM essentially the PCM is useless except to the original tuner. However I do offer an unlocking service for $75 to unlock most LSX PCM's.
