Hondata

I finally got this problem fixed. Fuel pump relay was burning out. Replaced it and all is good.

All are done and were checked.

There is no error code other then the "daughter board" error.

BTW, datalogging helps little since it cuts out everytime the error happens.

I originally was having a "daughter board communication error". This has now progressed to maybe a sensor problem.

Driving the car, CEL will come on (above mentioned error). When this happens the car will not accelerate when the gas pedal is pushed but it sounds like it's reving to the 4000rpm ...

Thanks for the info.

Again the problem happens. My ecu was sent to Hondata and is fine. My charge system was tested by Honda and is fine.

did that when I tested it on a different car and the problem never occurred.

Yes, the 7th gen civic is much easier for engine swaps because the wiring is very close to the RSX. Some models have wideband o2 sensors as well.

It sounds like an output or sensor from the ECU is being shorted to either 12V or ground. This then shuts the ECU voltage regulator down and therefore ...

Nevermind

Problem alleviated.

I think I may have found the problem. I checked the fuse box and the a/c condensor relay was loose. I secured it and haven't had the problem come up again.

Checked the ecu and connections. Nothing seemed loose.

The only error code I got was "Daughter board communication error". I did recently (prior to this problem) turn my OBDII on to check for any DTC's and got P1298 and the secondary O2 sensor error. Although I am not running a cat so I figured ...

This error seems odd and something simple.

I don't think 7thgen civics would have this problem then since they are very similar to the RSX.

I understand the concern from you guys. I guess it's easier to point the finger to the ecu then the harness.

The rough idle is unrelated to the daughterboard error. None of the engine swap harness I've examined supply keep alive power to the ECU. That means that the ECU never performs idle learn and the idle will never be smooth. The idle valves get sticky too.

I never knew that. Good heads up.

There ...