Hello all,

I have successfully read and saved my stock rom. I had a lot of trouble getting it to read correctly but eventually got it. I had to drive my car around for a many times get her warmed up and battery charged up a bit. I am only able read it if I click read with the engine running and give it some revs and even then it would read about 20-40% and quit. I even tried hooking a battery charger up but it did not help at all even though I was reading 14.2V from the battery. So at this point I am really worried about attempting to write back to it without bricking my ECU.
My question is does anybody know of a workaround to this? Is there something i'm missing?

 

Has anyone tried hooking a 12V power supply to their ECU during read/writes? I feel like that would be the perfect way to read/write the ECU without having to worry about battery level.

 

Is your battery dying? If so get a new one.
If not then its not the battery causing your problems, with a good battery you should be able to read and write while the engine isn't running.

 

minibattery?

 

It is a stock sized battery. I have cleaned the posts and they have a solid connection. I have never ran it dead but it may be on its way out though. I will clean up the negative side where it hooks to the chassis later and test it again. I did hook up a battery charger as I attempted to read the ECU that should take the battery out of the equation though... I would assume anyway.

I would like to build a bench test/flash setup at home sometime.

 

ECUFlash will not apply a flash if the voltage drops below 12 V. For a standard size lead-acid battery, should be no problem to maintain 12+ V with key on, engine off. If the rest of your charging system is in good shape (seeing 14+ V when the engine is running), then I think your battery is toast.

 

I reread your first post. Odd that you are having problems even with 14.2 V at the battery. What does EvoScan read if you log voltage with key on, engine off? If its reading 12+ V, I'd be leaning towards the possibility that your OpenPort cable is defective.

 

That is kind of the direction I was leaning as well. I will check the voltage through Evoscan later on and report back. Im assuming that checks the voltage right at the ECU. Another thing I noticed was it would not even attempt to read unless I started the car first and then clicked read. It would kill the ignition and then read about half the data then crap out. I did magically get it to read the entire thing but it took me a couple hours of messing around. I will not even attempt to write back to the ECU until I have this figured out.

 

Good news is that the ECU can't be bricked like the Evo 10 can. If a flash fails due to low voltage, it should be no problem to do a follow-up flash at proper voltage.

 

That is good to hear. So if it fails halfway through it would still be using the stock rom?

 

If it fails pary-way, it could be garbage code in the ECU. Definitely need to reapply a flash successfully if it fails part-way through. Point though is that failing part-way through will not make the ECU unresponsive to a reflash like it can for an Evo 10.

 

Ok makes sense. Im going to check the voltage through evoscan tonight. Im going to test it with and without the battery charger connected to see the difference.

 

*Solved*

So i did a few different things today. First i checked battery voltage with car off 12.6V. Then with it on but not running dropped to 12.1V. I hooked the battery charger up and got about 14.3V with the car off. With it still hooked up and car on it still dropped to 12.1V. It just cant keep up with the load. I then jumped it with my truck running which had a consistent 13.9V. I did a successful read first try this way!

Basically as mentioned I will just get a new battery.