Hondata

I have been using my s300v3 in a p28 to control my fan via A12 signal from the ecu. Recently I am getting no voltage output from A12 even when Hondata shows that FANC is active. Any ideas what to check?

I updated the software and when trying to update USB drivers I get an error that it failed to update.

You do not need to update USB drivers, as they have nothing to do with this issue.

Are you using a relay to operate the fans?

Yes I am using a relay. I tested for a signal at the relay and also at the ecu and I got nothing.

It has worked okay for years and just suddenly stopped.

If you use another output form the ecu using the aux outputs, does the relay work and turn on the fans when conditions are met? If the relay is bad then it may have damaged the ECU output.

The relay I had on it was bad and I replaced it. So I’m guessing that it damaged the output then.

Is there a way to repair the output, or to know which components were damaged? Or will it require a new ecu.

Otherwise I will need to run the fan from a manual switch.

You can try and trace it to a components, but that could be very time intensive and may still not fix it. We do not repair ECU's so it is probably best to use a different ECU with the s300.