‘03 Volvo 670 D12 EPG shorts out in cold weather

As the title says, 2003 Volvo 670 with a Volvo D12. EPG shorts out and throws check engine code in cold weather, but if I can manage to get the temp up to 160 (the temp at which the EPG then opens), shutting truck off and starting again the code goes inactive and works fine. Had physical problems with EPG as well so it got replaced, but problem still persists.

This doesn’t happen in warm weather, so I don’t think it’s triggered by simply having to close because the engine is under 160.

Also, like 5% of the time the EPG will whistle for a few seconds on startup but that only happens if the truck is already warmed up, or it doesn’t short out. And on startup, you can hear that the EPG is working for a while before it shorts out, so it’s not right away. Couple minutes after running fine it’ll short out. EPG fuse blows and causes warmhold fault.

Thanks for anything anyone can do!