while putting some loud horns in my 2004 Evo 8 gsr, my buddy hooked the battery up backwards. this is in the middle of a clutch exchange as well, everything is apart and ripped out as far as the drive train is concerned as well as exhaust. the battery stayed like this for a while (30-60 seconds). the head lights came on by themselves, and some smoke came up by the center of the windshield.

friend works at mitsubishi, said i need a new ecu..

1) what damage could of come from this?

2) how can this be fixed, stock or aftermarket?

 

damn that sux, theres always ecu's for sale on here, i'm not a guru so i dont know if u can swap any one in, or if u need one with your actual rom ID. I had a buddy help me with a clutch install awhile back and he broke a chunk off my Tcase! dont ask how, but atleast i got a built one out of the deal

 

It was probably the battery smoking. Hook it up the right way and see if stuff comes on?? I wouldn't get anything till you get the car back together, then decide!! Aren't there fuses all over the place to protect from frying anything but the battery if this scenario occurs??

 

I see you let the factory smoke out of the battery.
-- I wouldnt do it again but Im sure your ecu is fine. I would guess you just popped some fuses,so I would check for that. The smoke was more than likely coming from the battery and lingering around the engine bay trying to escape out.

 

Yup, start checking fuses. I'm sure you smoked several in the fuse box under the hood, and steering column. Try connecting up the battery correctly, then connecting to your ecu with a tactrix cable. If it sees the ecu, you're good to go. Don't turn the key on though, since you have all those connections for the clutch disconnected.

 

it wasnt the battery... the battery was on garage floor, and we jumpered it to the battery leads. this was deffinatly coming outta the center windsheild, between hood and windshield. ill check all the fuses tomorrow and get back to you guys.

ALSO, the key was turned while everything was apart... what now? i think my buddy mentioned something about "limp mode" lol? basically wont go faster then 50k untill codes are cleared? any truth to this?

 

Center windshield... Not sure where the alternator is connected but I've accidentally done that one time on a different car (touched the wrong lead on an alternator) and it started going nuts, lol.

You won't be in limp mode :/ If your ecu is ok and all the fuses are good to go, once you disconnect the battery you dump all volatile memory so...

 

Teach your buddy colors and symbols, this is a +...rrr rrrrr RED...this is a -...bbbb...bbb...BLACK!

Ok anyway, the "limp mode" thing is something I've never heard of...ever. As for fuses, yes, they're there to protect everything. The smoke could have been from wire shielding melting due to the battery mishap.

The key was turned as in you guys tried to CRANK it or just to ON?

 

Limp mode is something EVOs will go into to protect itself from completely destroying itself in the event of an imminent catastropic failure of certain components... At least that's what I've gathered from reading numerous posts on it, lol. Basically like if your tranny gives a code that basically says it's not going to work right, the car will go into limp mode and not allow it to go into super sport mode on the tc-sst trannies or into a certain gear or over a certain rpm/mph. That's the just of it )

*EDIT* not just trannies but the engine, ECU, or multiple other items. If something fails a diagnostic, or you do something stupid with your car, limp mode FTL.

 

did NOT try to crank it haha, just into the ON (accessories) turn.

so... being in limp mode i do what? just disconnect battery after everythings together plumb and proper with good fuses? if it doesnt work then i need new ecu? ill test it with that tactrix cable soon as i learn how.

thanks for everyones help so far! worst case scenario, how much is an ECU?

 

limp mode means your car still works... like I said you're probably not in limp mode. The only way to find out is run the car and drive it around. ECUs are supposedly extremely cheap. Check the For Sale section out.

 

If you just turned the key to the ON position. Any electrical with an associated check engine light code will most likely show it's face. Either re-flash the ecu with your current rom, or clear the codes with a diagnostic reader. As for the smoke..maybe investigate by removing the plastic piece around the windshield. You may have smoked the wiper motor, or as previously said..melted some wiring insulation.
Did you try to connect to the ecu yet? With either ecuflash or a OBD reader? That will confirm if you fried it.

 

It's pretty simple to remove a cowl on any vehicle as it's usually just unbolting the wiper arms and pulling it or removing some plastic clips. I'd start there and look under to find the source of the smoke...

 

street bike lessons have me beet, ill check it come monday night and let you guys know what i find.

 

Oh man that is sad.
Sorry to hear mate hope it all works out well for you.

Cheers