Hondata

I installed the boost controller hardware in my ecu sometime ago and we are now tring to use boost controll option with hondata solenoid, but the car would continually over boost. We found out that with this ecu connected it is leaving solenoid wide open for some reason. Because when I install another customers ecu in my car which I also had installed the boost components into the solenoid seems to be working correctly. So my question out of the components added for the boost control which maybe causing solenoid to be wide open, so as to narrow down the trouble shooting of this? Other then this issue with boost control components the ecu works flawless. I looked over all solder joints everything looks fine other then there looks like some slight heat discoloration on the metal part of the large transistor.

Make sure that the components are oriented correctly and in the correct locations. If they look correct, then you may have damaged a component when installing them. There is no way to guess what component it may be.

it is also possible that driver transistor is burnt causeing a power short to the component. I suggest verifying that the driver circuit works with a headlamp being the load... not a test light. If it is on all the time regardless of your command then I would suspect that there is a faulty driver transistor in the ECU that is not turning off the component.