Think I fried my year old v3 ecu.

[crash89]

Hope this is in the correct spot as it has to do with link v3. Also I posted this on the link forums and wanted to see what your guys opinions would be.

I feel like an idiot, I shorted out my battery yesterday. Anywho, when I did that I blew my 100a alternator fuse, as well as the fuse to my amplifier. So, upon trying to start my car after just getting it all back together Im getting no fuel and no spark. Also when I turn the key to the "on" position my CEL does NOT come on and I cannot connect to link.

When I try I get a message that says "Scan failed to find a working connection".

I tried my spare stock ecu and turned the key to the "on" position, I got a CEL. I dont have any stock injectors otherwise I would have tried to see if the car would fire up with them and the stock ecu.

Question is, what should I expect here? Do I just need a new 2g eprom, or would the software be damaged as well? Could this be repaired? If it can would I just send it back to the guys at link or something I could do myself? I couldnt see anything that looked out of the ordinary when I took the top off. No funny smell or burnt areas.

Thanks guys.

 

[snowborder714]

My guess is you blew D103. If this is the case, that ECU is dead (unrepairable) and you'll need a new one.
reversepowered2g [ECMTuning - wiki]

Post a picture of the circuit board though and zoom in on any areas that look blown if that's not it.

 

[crash89]

Alright. Ill have to run back to my garage and grab it.. Pics in about half hour. I sure hope this can be repaired and Im not out a ton of money.

 

[Arthris]

## stock ecu may be the flashable one. If so you do not even need link. Compared to the Flashable ecu's link is childs play. Link is great but ## working with a old tech. The flashable ecu's are much faster than the 95 ecus. Check this out and see if ## stock ecu is flashable H8 ECUs « ceddy.us then you can go from there or find another 95 EEPROM ecu. Most likely you fried the ecu and not the chip. You could send to link and see if they can repair it.

 

[snowborder714]

Please, let's not get into the link vs. flashable ECU debate We all have our own opinions on what's better. This isn't the thread to voice those in.

 

[crash89]

Yes I have the flashable ecu. I didnt like it.. It wasnt as easy for me to understand and grasp so I just spent the money on an EPROM and link and went with it. I do still have the tactrix cable around somewhere so I might be able to find someone to help me out.. however that'll be addressed later..

Sorry it took so long to get the pic. Was having trouble getting it uploaded. So because it looks like this and not the third pic in the link you posted it means it isnt repairable?

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[snowborder714]

Yup, that ECU is toast if it's not working for you.

I personally have never seen any ECU that's popped that diode and been able to be repaired. Not sure if Tom has or not, but I'd bet it'd be a very rare situation.

 

[crash89]

Well fvck... So could I just get another socketed eprom and just put my link chip in it and be ok? Or would I have to send that one back in?

 

[TSiAWD666]

Don't feel too bad. Did the same thing to my track car by putting jumper cables to my car and reversing them. Happens man, just get a new ecu, have the socket transferred from this friend one, and hopefully your v3 chip will still be good.

 

[snowborder714]

So could I just get another socketed eprom and just put my link chip in it and be ok?

Correct. I've yet to see anyone fry their EPROM chip. Usually it's just the ECU.

 

[crash89]

Don't feel too bad. Did the same thing to my track car by putting jumper cables to my car and reversing them. Happens man, just get a new ecu, have the socket transferred from this friend one, and hopefully your v3 chip will still be good.

Well I made the mistake of having my battery in backwards.. Stupid small STM battery. Started rushing because I was getting excited to have it back up and running and pop spark boom.. ####..

Well damnit.. Thanks brian for the help. Hope I can find another eprom around here for the cheap.

 

[snowborder714]

Well, if you mentioned that in the first post, I would've been more confident in my reason why it wasn't working. Reverse powering sucks - I've seen too many friends (including John) have it happen and I hate diagnosing it.


You shouldn't have any issues finding another ECU. I've seen them going for $130-$150 all day, with some of them even being socketed.

 

[crash89]

I bought the one I have now for like 65 bucks last winter. Hope I can get another score like that.

 

[NHerron]

Hey does anyone here know of a way to prevent this? (sarcasm aside )

I'm talking like a reverse polarity control circuit connected from fuse box to ground or something. I mean really, if high tech battery chargers have the protection, what is it they use? I'm kind of surprised our cars didn't come with it, don't most cars today prevent this with some simple circuit?

 

[donniekak]

Hey does anyone here know of a way to prevent this? (sarcasm aside )

I'm talking like a reverse polarity control circuit connected from fuse box to ground or something. I mean really, if high tech battery chargers have the protection, what is it they use? I'm kind of surprised our cars didn't come with it, don't most cars today prevent this with some simple circuit?

Really large diodes.

 

[NHerron]

I'll see your lazy answer and raise you sarcasm!

What are diodes? Is that like a flux capacitor? And how big? Like half a battery big?


Just kidding donnie

But seriously, I know electronics so is there an aftermarket thing for polarity protection these days?

 

[fwbt]

Reverse Polarity Protection.

This has a couple of ways to prevent reverse polarity situations each with a list of advantages and disadvantages. Short of building a bridge rectifier and having that directly into the the battery and to the cables it seems a rather inconvenient system. As well with anything electronic device, not if, but when it fails it could be at a most inopportune time.

 

[NHerron]

Nice post Jim, funny, I was just thinking about a simple relay to protect the ECU, but not 100% on what wires need be protected. If it's just the main switched and battery backup wires going to the ECU needing polarity protection, couldn't we make a simple diode controlled relay activated circuit for the ECU power wires?

Basically for the relay to turn on you would need say +12V on pin 1 and -12V on pin 2, if it's anything else it won't switch the relay, therefore ECU has no power. I guess I don't know how to protect if someone were to jump start the car with their remote jumper cables reversed though. But I wouldn't think that would hurt anything, I don't know if current flow would actually be effected in that situation.

 

[fwbt]

I'm likeing the rectifier because, if the jumper cables are hooked up improperly, the only feasible way to prevent that would be a setup where a full rectifier is used. Then as long as the jumper cables weren't hooked into to the battery itself, the car wouldn't essentially care. I think it would be a really cool concept to try with a GM style battery and top mount the kit.

As far as protecting only the ECU... I'm not 100% on 2G schematics, but the 1G only has one battery backup circuit. I don't have a 2G EL book to compare but are both circuits fuse protected? I've accidentally reversed my jumper cables many years ago on a 1G and had no significant issues outside of blown fuses. Honestly, that would kind of surprise me if it wasn't but then it would really become a sujective matter until someone wished to prove it by sacrificing a ECU.

 

[fwbt]

Additionally wouldn't removing the battery backup cause issues in places that have OBD-II readiness requirements?

 

[NHerron]

Wouldn't the bridge need to support the total systems load? I'm thinking of the starter motor when it first hits it peaks well over 500amps, could a bridge deal with that quick initial load?

I'm a bit confused on why fuses blow when two separate systems are hooked together other than a parallel basis though. When you arc battery terminals together with a wrench, no fuses blow. I guess in my mind hooking two batteries together like that, it's their small world and can't see why it effects outside that.

I'll see if I can find what I'm looking for on Google too

I read a few articles, starting to make sense. On a side note look what Nissan uses:
http://autorepair.about.com/library/a/1d/bl556d.htm

 

[fwbt]

The rectifiers that I have in my power supplies at work support well over 500 Amps constant power and are the size of a small shoe box. Keep in mind that they're also converting AC/DC as well. I'm almost convinced that it's the backup pins on the ECU that are being toasted. In the OP's case it seems that he just hooked up the cables and that was it. I suppose that if you had a NC STDP relay. Put the ECU grounds on the pole side and have the incorrect voltage actuate into a open status that would likely work. The only downside to this if the switched voltages are actuated the ECU likely would be shot again.

 

[crash89]

Dont mean to disrupt your guys convo.



Bryan, Tom Dorris just pointed out something to me on link forums.. Take a look at the third picture in your link then a close look at my picture. I think my ecu will be save-able!!!

 

[snowborder714]

So that track is actually blown? I see some discoloration, but it looks like the track is still in tact to me. Not the best picture and my eyes aren't the best

 

[crash89]

I hear ya on the eyes being bad. Its hard for me to even see and I had the thing right in front of me. I sent my ecu out to ecmlink today. Hopefully Tom gives me some good news when they receive it!