flashing 94-95 lt1 .bin file on a 96-97 lt1 computer?

[jrgcjnl]

my question is can you flash an obd2 computer with an obd1 bin for an lt1 instead of buying another pcm?
they look the same thats the only thing that i think changes, the bins itself

[EagleMark]

I've been wondering the same thing but haven't had the balls to brick a good PCM... yet...

[jrgcjnl]

haha yeah, well anyways, I'll see if it works on my old 96 pcm, I don't have much to lose, if it doesn't work ill just tell my brother to reprogram it at the dealership for free :)
oh and if it works ill let you guys know :thumbsup:

[EagleMark]

I just got a set of PCM plugs with pigtails so I can read and bench program this PCM, I've got a couple OBDI spares but no OBDII or I would at least pull it apart and see how much has really changed inside. From what I have seen in wiring diagrams there's not much difference except the crank sensor on 96 OBDII.

[jrgcjnl]

so... does that mean you think it may work?

[EagleMark]

Yeah. But it's only a theory until I ruin one... :laugh:

[RobertISaar]

pop it open, take pics, especially of the PROM(s). if i had to guess, i'd say that's going to be a hurdle.

[jrgcjnl]

me? lol
and its not too hard to mess with it, i had to solder a resistor into my current pcm to use my 96 knock sensor with my obd1 pcm so i could just swap them whenever i had to, and it works great too (the resistor mod)

[RobertISaar]

sure, if you have one that you can open up.

my guess is that the PROMs changed when OBD2 was implimented... i'm kind of wary about all of the OBD2 added stuff fitting in 128KB of space that the 94-95 have.

if the PROM changed size, i can guarantee that attempting to flash it with a 94-95 LT1 BIN will cause immediate bricking. and the kind that you won't necessarily be able to unbrick without desoldering the PROMs and flashing them using something like a MCUmall unit.

[EagleMark]

Strange thing is if you look to buy a bench top program cable they are the same part for 94 to 97. So I built one today, works fine on OBDI on bench. Now I need an OBDII victim to open up and see if eeprom are different, if not, then try to BRICK it... would make a cool doorstop for shop!

[romac55]

Strange thing is if you look to buy a bench top program cable they are the same part for 94 to 97. So I built one today, works fine on OBDI on bench. Now I need an OBDII victim to open up and see if eeprom are different, if not, then try to BRICK it... would make a cool doorstop for shop! You'll let us know how badly you fry that ECM , won't you ? Is bricking your ECM the same as "bricking" your camel , to get him to cross a 7-day desert ? The experiment will save a lot of us a ton of grief downstream , especially if it works . Good question , good thread. Be safe...Bob.

[EagleMark]

Didn't get a chance to brick one... found that it is not possible.


'94-'95 LT1 is an OBD1 PCM w/flash memory, '96 and newer LT1's are OBD2 w/flash. Different PCM part numbers, completely different base code, connection protocols and tune data.

[jrgcjnl]

Sorry guys my home internet has been out for awhile so im installing some coated pacesetters
and those were the responses i got on another forum, it cant be done
Sucks cuz i have a spare obd2 computer but no one can use it

[EagleMark]

are you selling it? How much?

[jrgcjnl]

Not really, its basically just a back up in case i need the original