LT1-LT4 Modifications 1993-97 Gen II Small Block V8

PCM is dead. Can tuners usually fix?

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Old Jun 29, 2016 | 09:13 AM
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Default PCM is dead. Can tuners usually fix?

I was getting no spark out of my car (no 5v to the opti), so I checked all the PCM grounds and pcm power feeds, all good. Even checked, the PCM was not spitting out 5v at the source.

I swapped into my beater. PCM still didn't even start the car, so I know it's bad.

Anyway, wondering if I should buy a new one or try to send this one to a tuner for repair?
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Old Jun 29, 2016 | 09:19 AM
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Doubtful you will find someone to fix it. LT1 PCM's are outdated now. Pick one from the junkyard
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Old Jun 29, 2016 | 11:02 AM
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tuners can fix problems with the flash chips but the rest of the board is probably not worth fixing. not having reference voltage output is bad news and not related to programming.

i agree, throw it out and get another one.

but now the hard part, you have to figure out why it died.

i've never seen an lt1 ecm just die on its own (and you have no idea the horrible things i've put them through), it's likely a wiring fault caused it.

you have to figure out what killed it, or your next ecm will surely suffer the same fate

the last ECM i cooked was due to the engine ground wire being disconnected for a long period of time. it ran like crap, then just stopped working.

im selling a socketed ecm with a programmer right now on ebay if you are planning to do a lot of tuning in the future... http://www.ebay.ca/itm/252439692821
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Old Jun 29, 2016 | 03:39 PM
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Thats a good price that Stevo is selling it for, I would jump on it, I sell them for $150.00
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Old Jul 1, 2016 | 02:31 PM
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Its not completely worthless to try to fix IMO. Crack it open and see if you can find any damaged or burnt components. Components are still available and if not, a suitable replacement could probably be found. If you find something damaged or to far gone to read the PN on the component, I have a couple of ECM's I can take apart and get you a proper PN number.

So I'm not trying to high jack the thread but I do have a question for steveo_.
I have a ECM that i had once tried to program. To make a long story short I walked away for a few minutes then came back and the programmer stated that it had failed and basically killed the ECM. Could repairing the ECM be as simple as replacing the flash chips and reflashing ecm or does the flash chips require a "boot code" installed before flashing. ECM is out of 95 BTW.
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Old Jul 2, 2016 | 02:04 PM
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To answer, the chips require a type of programming, there is the T side and E side, I use to repair the OBDI PCM's but just don't have the time anymore but I do have the real intel chips ready to install for $40 a pair. You just have to be able to solder.
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Old Jul 7, 2016 | 09:33 AM
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Originally Posted by J-13gtp
So I'm not trying to high jack the thread but I do have a question for steveo_.
I have a ECM that i had once tried to program. To make a long story short I walked away for a few minutes then came back and the programmer stated that it had failed and basically killed the ECM. Could repairing the ECM be as simple as replacing the flash chips and reflashing ecm or does the flash chips require a "boot code" installed before flashing. ECM is out of 95 BTW.
in fact it's likely as simple as replacing one flash chip. you do need to program that chip with a working bin first.

you can likely identify which side is dead using raw commands with my eehack software (pm me for details...).

there is actually a way to do a reflash in-place without removing the chips (assuming the flash memory is still alright), in fact the board has a diagnostic header for such purposes, but the hardware is custom and undocumented.. i started trying to build one but gave up.

you can send it to the guy that writes tunercat and he'll do it for you really cheaply.... my hunch is he has such a rig.
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