: Re: LS1 - Flash - Reprogramming

Speartech speartec at iquest.net
Fri Nov 3 00:56:32 GMT 2000


Andrew, Bob, and others:

After many hours of investigation I am able to reflash the LS1 PCM's with 
an export VIN for my streetrod engines. This allows me to set the engines 
up w/o EGR, cats, A.I.R., or post-cat O2 sensors, which is what most of my 
customers prefer, but it would sure be nice to do much more with the 
calibration!!   I have access to a few of the chips; Intel flash 28fn400 
??......I don't have one in front of me, that is probably not the exact 
number.  What programmer are you using to read these?  It looks like a 44 
pin chip; do they sell an adapter for it, or is it DIY?  Also if someone is 
going to dig deeply into this, I would suggest starting with the 99 and 
newer box.  The 97-98 LS1 PCM was obsolete after 98, while the 99 and up 
covers the Gen 3 truck engines as well as the LS1's. Although I don't know 
for sure I am guessing the new L18 big block (8.1L ,496 C.I.) probably uses 
this same box since it is 24X, SFI, and coil per cylinder like the above 
engines.

		John

 >Bob wrote:
 >>
 >> I have recently gained an interest in having the ability to custom program
 >> the LS1 ecm. People are obviously doing it but there doesn't seem to be any
 >> "end user tools" yet. Reviewing the list for the last couple of months 
I saw
 >> that Andrew K. Mattei was getting into the flash memory of an LS1. Andrew
 >> can you tell me where you are with this?
 >
 >
 >I got the chip off the board, put it in the programmer, and read "FF"'s.
 >Need to do some troubleshooting on my piggyback board. Those chips are
 >VERY fragile, so I hope that I didn't break anything. I don't think I
 >did, but still need to do some looking.
 >
 >> As I understand it the obd2 specification requires encryption of the data
 >> going to / coming from the ecm. Has anybody broken this encryption?
 >
 >
 >None of us, AFAIK. Steve Cole, yes. Hypertech, yes. Us (anyone on this
 >list, AFAIK), no.
 >
 >> If the encryption has not been broken that means the flash memory must be
 >> accessed directly. From what info I have been able to gather (having not
 >> opened an ecm (yet)) the flash memory is surface mount technology. Does 
that
 >> mean that the current "turners" are unsoldering, reprogramming, resoldering
 >> the surface mount flash memory chip (doesn't sound like fun to me!). Maybe
 >> there is some other way, I hope.
 >
 >
 >No, they are not desoldering. I do not see how you could successfully
 >remove, program, resolder one of these chips without coming close to
 >frequently breaking them. It's that fragile.
 >
 >> I also see that Steve Cole has this power loader there appears to plug in
 >> somewhere. Does anybody know how this works.
 >
 >
 >I've talked to him about it. You tell him what you need for your LS1, he
 >ships you a custom program built in to a Powerloader. You plug it in to
 >the car, hit a button, and bam, that's it. No options, no reversal. If
 >you need something changed, you send him the powerloader, he changes
 >stuff, he sends it back, you hit the button, bam. It's programmed. It's
 >basically a one-shot device, unless you need a reprogram. It beats
 >having the PCM lost in UPS land for days, though.
 >
 >
 >- -Andrew
 >- 
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