inconsistent heat

[LightlyToasted]

ISTA performs a similar function, but I haven't yet found a way to read the individual temperature sensors in the heater core nor air vents nor interior. The coolant temperature and outside temperature can be displayed on the instrument cluster via the hidden menu.

I think the IHKA believes it needs to quickly ramp up heat so it ramps up the blower and blasts warm air for 30s, then it lowers the blower and reverts to cool air for about 10-15s. Then the cycle repeats. It's either getting bad data, or is itself faulty.