Heaters playing up…

[Summertime]

Hi, hoping someone can help.

I’m getting lukewarm air from my f80 m3 heaters unless I turn it up to max. Seems to be less air coming out / being blown out the vents too.

I’m trying to get hold of ISTA to do some more rigorous code reads, but the basic code reader says no faults?

Only thing I did see on the basic code reader was that it said ambient air temp was 19 degrees Celsius whereas it is actually about half that - not sure if that is related or not?

Any ideas on how to fault find?

Thank you

[Summertime]

So checked using ISTA and there was no error codes.

The air distribution flaps seemed ok too.

The only thing I noted was the internal cabin temp sensor was showing a c3-4 degrees Celsius higher than what I think it was - so I turned the temp up to max the cabin got very hot, but when at my normal 22 degrees it was pumping out Luke warm air.

Now thinking it might be that…but looked on real OEM and couldn’t see where the cabin sensor is located?

What do people think? Anyone else had the same issue ever?

[WhiteFox]

Internal temp sensor is faulty and will need changing hence when this goes faulty you will only get max heat at max as overrides the temp sensor.

[Summertime]

Thanks, looks like you have to buy the entire HVAC control panel and cannot just replace the thermostat.