2015 No Heat

My 2015 SV is behaving strangely in the cold (15f) and I am hoping someone can help troubleshoot.

Heat set to 90F, fan on 3 and recirc on.
I get a little heat and climate energy use is about 1.4kW.

As soon as I turn on the front defrost the A/C light comes on.
Recirc off, cold air blows and climate energy drops to 0kW.

In warm weather the A/C works great and blows fairly cold so I don't think the a/c has issues.

From what I have read there is supplemental resistance heat in the very cold. I am guessing this is not working and the 1.4kW I am seeing on the energy screen is just the heat pump? How do I definitively diagnose if the resistance heater is dead?

Why on defrost does the energy usage go to 0? I would have thought the a/c or heat pump would still work and draw some energy. Just seems strange that if it is cold and the a/c light is on the climate energy usage is always 0?

Can anyone shed some DIY troubleshooting light on this?

Thanks

There is a glitch in the energy usage programming that apparently shows no increase in energy consumption with heat and air conditioning on at the same time. I think that this is the case here, and that you are correct about the resistance heater having failed.

Leaf Spy may show some useful error codes.

Looks like I have the infamous B2773 & B2774 codes. Has anyone taken the PCT heater apart to try to figure out what goes wrong with them?

ScottAi said:

Looks like I have the infamous B2773 & B2774 codes. Has anyone taken the PCT heater apart to try to figure out what goes wrong with them?

Click to expand...

Yes. Sometimes it's a blown fuse, although that raises the question "Why did it blow?"