What's the procedure to run an AC module self diagnosis? For other Lexus models i see you have to press at the same time Auto + Recirculate. However, the IS doesn't have an auto button (just a position on the dial).

Problem is i'm getting no heat (or extremely little heat) in the winter - and the AC is blowing lukewarm air in the summer.

The interior temp sensor is working fine - tested it with a heat source, the temperature servo motor starts moving (as it should - i think...).

So to the temperature motor / stepper / servo or whatever it's called is working fine (i even tried removing it and moving the lever attached to it by hand - still no heat, no matter the position).

The ac mode position servo is also working, the recirculation servo is working and so is the fan.

The heater pipes - one of them is not insulated - could not check properly if it was hot or not, but the other pipe (not insulated) was hot.

Trying to diagnose this thing before i start tearing the dashboard apart... any help would be appreciated.

 

Already started to help on the other forum.