ECUFlash: Test write or not?

[jay-d]

So, I bricked my ECU in the beginning of January and I finally found a used one that I'm getting my mechanic to install.

 

I bricked it by pressing test write, which was successful and then pressing write without cycling the ignition. There was an error that I didn't catch, thinking it was nothing but all communication with my ECU was lost.

 

So my question, how many of you test write? If you do test write, do you cycle the key after the test write is completed? What's the proper sequence as I'm a little nervous to flash my 4th revision.

[gimpydingo]

I've always test written, looked for errors, if none then write/flash. I didn't cycle the key.

[solidxsnake]

I've always test written, looked for errors, if none then write/flash. I didn't cycle the key.

 

This. There's no reason to cycle the key. Make sure you have no errors, and flash. If you see an error, don't kill power to the ECU! Once you lose power to the ECU and it's got a bad flash, it's possible that it'll be bricked.

[jay-d]

That's what scaring me.. in the past, I recall test writing, and then pressing write. But for whatever reason this last time, I test wrote and it completed, but when I pressed write, nothing happened, it errored and that's when I cycled the key.

 

One other thing that was different was, I had the USB cable for my wideband o2 sensor plugged in.. any other time in the past, I never had it plugged in. Maybe that's what caused ECUFlash confusion and bricked my ecu.

[solidxsnake]

That's what scaring me.. in the past, I recall test writing, and then pressing write. But for whatever reason this last time, I test wrote and it completed, but when I pressed write, nothing happened, it errored and that's when I cycled the key.

 

One other thing that was different was, I had the USB cable for my wideband o2 sensor plugged in.. any other time in the past, I never had it plugged in. Maybe that's what caused ECUFlash confusion and bricked my ecu.

 

Yes. What I'm saying is that the test write wasn't your issue. You bricked your ECU as soon as you cycled the key. For future reference, if you get an error, keep the key in and try re-flashing. Try doing other stuff (unplugging your wideband, etc) if you keep getting errors, just exhaust all other possibilities before you power the ECU down. If it's got a bad ROM on there at power down, it's likely it'll be bricked and you'll need to flash the ROM externally.

[jay-d]

Yes. What I'm saying is that the test write wasn't your issue. You bricked your ECU as soon as you cycled the key. For future reference, if you get an error, keep the key in and try re-flashing. Try doing other stuff (unplugging your wideband, etc) if you keep getting errors, just exhaust all other possibilities before you power the ECU down. If it's got a bad ROM on there at power down, it's likely it'll be bricked and you'll need to flash the ROM externally.

 

I'll remember that when I go to flash tomorrow, thanks for the insight!

[mondtster]

I never bother test writing anymore. I just write and if there is a problem I deal with it. As someone else said, if there is an error detected it will say so and DO NOT turn the key off. If you do the ECU will be bricked.

 

I've tried writing a lot of different files to my ECU, many of them something different than what should be in it. If there is a mismatch warning boxes will pop up. When in doubt I revert back to a known good file to make sure I don't brick my ECU.

[covertrussian]

I noticed that test writing preloads the rom into your RAM thus the actual flash is faster then. But your right, test writing is not really a must, I've had numerous times that I test Wrote and then still had a flashing error (I think my Tactrix USB plug was on it's way out causing this), rewriting it saved the day though.

 

It got really scary when I started modifying my 2012 outback definitions and didn't do something right, so ECU flash would crash after running for a few minutes. Needless to say I was scared and stopped flashed my cars until I figured that out and got it fixed (by doing a fresh install haha).