Hondata

Hello,
Having a bit of an issue with my 2009 FA2 Si....my son was driving it, and he heard a bang, and noise under the hood when driving. Somehow limped the car home, and upon inspection found the following:
-Serpentine belt gone
-upper motor mount broke off
-Alternator seized (discovered after)
-Fuse 19 (15A FI main) blown
-Dash display has a blacked out temp gauge

Troubleshot the blown fuse, by removing relays/ECU, and the fuse stopped blowing after the ECU was removed from the circuit.

Bought a new/used ECU from another Si (upon receipt it looks like its from an FG, so I hope this is not the problem), replaced the alternator/serp belt.

The fuse no longer blows, but I still have the dark temp gauge, and no start (but it does crank). Unfortunately neither the Hondata or my scan gauge will communicate with the ECU.

So I see two main issues: I need to get the new ECU programmed somehow (dealer or a snap-on tablet), and then I need to somehow unlock my Hondata from the old/fried ECU, and lock it on to the "new" ECU.

My Hondata Serial number is FP-Si-US-13914

Thanks in advance!

I would recommend that you put your ECU into a working vehicle and see if you can return to stock. If you can, then the ECU is probably not the issue and you need to correct the wiring faults in the vehicle then try your ECU in it and see if it works. Only replace the ECU as a last resort after everything else is fixed. If you cannot return to stock, then the ECU is probably damaged and would have to replace it. Keep the damaged ECU to be able to unlock it.

OK thanks for the quick response, I will give that a try.

I did re-test the original ECU back in the car, and the fuse popped immediately. Replaced back with the replacement ECU, and the fuse did not blow....would that in itself say that the problem is in the original ECU itself?

Thanks again

Not necessarily

Wouldn't a shorted/seized alternator fry an ECU? Or are you thinking that there is a grounding issue (that only seems to be present with the old ECU)?

You should still try what I hav suggested and see if you can properly return to stock and unlock in a working vehicle.

I have a fried ecu as well. Put in a working si and still get no power to fuel pump and temp gauge is dark. Si I put it in is running with its original ecu as well so I know it’s the ecu. I’m trying to unlock the flashpro from the ecu but it’s saying it doesn’t recognize the vin. Which ends in 619 and that’s on the tag of the car as well. I need this unmarried from the ecu so I can then marry it to the new ecu I have installed so I can tune it. What are my options?

With everything plugged in and the ignition in the on position, go to the Help menu and click on “send feedback”. Include a detailed description of the issue.