Asylist

When I go searching the junk yards this weekend for an ECM to replace the one my Hypertech fried yesterday, what options do I have for replacements? My car is a '96 LT1 M6 car. Does it have to be specifically a '96 M6 ECU, or can I get one from a '97 as well? Obviously I can't go '95 or older, as those are OBD-1, and I'm guessing that a '98+ would be different as well as the electronics on a LS1 are different. Also, if I got one from an auto, obviously the tune is different, but would it work enough to at least make the car driveable until I can get it reflashed to a M6 tune?

bobdec

You really need a PN 16214399 or 16242921 PCM that is for a M6. Those PCMs were also used on F-Body's, and B-Body's Impalas, Roadmaster's and some Cadillac's with the LT1 engines, probably not to many M6's out there. Is you PCM really fried or just messed up because of a code load going bad. If it's a load caused problem it can be fixed for about $50.00 ( http://www.madtuner.com/index.php?pa...mart&Itemid=26 ) just an example you can search on ' PCM flash repair' for other repair sites. If you put in an A4 PCM then you would need a tune to get things running OK (speedometer and error codes).

Asylist

I'm fairly positive that its just a failed code load, as it was fine before I hooked the Hypertech to it, and wasn't immediately after. Problem here is that this is my only car, and I need it running like yesterday. I know to expect errors and whatnot from a A4 computer, but if it means I can get to work with it until I can either get a M6 computer, M6 tune, or mine fixed, I can deal. But if it means the car won't be driveable at all, that's a problem. So that's what I'm really asking - whether or not the car would be driveable with an A4 computer, and what years would work.

bobdec

Pretty sure it would run SES light, maybe the fans will be on (don't know for sure) and of course speedometer. It may hesitate or stall at coast down stops due to IAC follower being controlled by speed. You will have a few DTC errors , but I don't think they will effect actual engine running.

brad3579

I am pulling my motor out tomorrow and have a computer with just under 20k actual miles on it. It will not be needed anymore as I am going with the 24x conversion.

Asylist

Went to every you pull it yard in town, and found only one LT1 car with the computer still in it - a '94 Caprice with a sticker on the hood that said it was a CNG car. To my knowledge those were all Bi-fuel cars, able to run on either CNG or gas. I couldn't find any of the CNG parts on the car, so it may have just been swapped on.

Yes, I know this is OBD-1, where my car is OBD-2, but like I said before - I just need the car running and driveable, even if it's not "right". in the mean time, I'll send mine out to get fixed/reflashed.

Ricardo

I fried one today too.
Its a 97 M6 out of an F body.
Gonna try to do the socketing.

Asylist

I'm REALLY tempted to socket mine too, as I can do the soldering part no problem (I can hand solder SMD a), so this would be no problem, but I don't have a EEPROM programmer. Although after the hassle I've been through this week, it might just be worth it to get one, lol

Asylist

After drive update - well, it's driveable....technically, lol. When I first plugged it in and fired up the car..it ran poorly, and that's still giving it a lot of credit, lol. Would barely rev in the driveway, sputtered and stumbled like crazy pulling into traffic, and had NO *****. Felt like I was driving a 200K mile 1984 four banger Camaro (and my engine puts down 300+HP normally).

After I drove it around the block a few times, it got better and smoothed out a bit. It still idles near 2K RPM while coasting with the clutch in, and drops down to around 500 RPM at a stop. Reverse isn't locked out while moving, thus getting into 5th or 6th gear is..."interesting" :P Oh yeah, and CEL is on and speedo is reading WAY slow (was reading around 25 when I was doing approx 55-60) But it did pick up power, and will roast the tires now if I stomp it in first gear from a roll. It's no where near where it was before, but should be enough to at least get back and forth to work until I either get another OBD-2 computer, or decide what to do with mine.

omega552003

sounds like the ECU is expecting 3 main things, different size injectors, VE table and Spark table. The ecu is probably go some wick fuel trims going on, like -25%

as for the Speedo, i be its a combination of you Tranny gear ratio, rear end ratio, tire size and the VSS. Tune the kinks out and you probably would be ok for 80% of your driving

Injuneer

The problem with the speedo has nothing to do with transmission gear ratios. The VSS reads the output shaft/driveshaft RPM. The major problem is the A4 programming expects 40 pulses per revolution from the VSS and the M6 only has a 17-tooth reluctor gear. Your speedo would be reading about 42% of actual speed, or reading 25MPH at a true 60MPH, +/- any minor corrections for rear axle ratio and tire diameter.