Every now and then I throw a
P1291 - No Temperature Rise Seen From Intake Air Heaters

like this evening on way to work, only on start up. I usually just reset the CEL and go on my way, but curious if anyone has experience with this code, or what I could check. I'm guessing the intake grid heaters, but they seem to work okay, voltage draw when cold, , wait to start, etc.

Thanks.