As per our guidelines we don't provide that information here.
i can only suggest you try codes you may think it could be.
If the system is misbehaving due to a power outage then something is wrong with it and it's in need of a service visit, they will be able to reset the code for you at the same time.
Adding a resistor is far easier than adding a power burning, heating up relay.
However I'm wondering does it need something like a relay to draw more current so it can turn the pin off. I'm going to try and locate a relay and I'll report back.