Disco 2 Climate control

I have a TD5 D2 ES with dual climate control. With 18 degrees set it blows hot air, with 17 degrees set it blows cool air. I'm guessing a fault with the internal air temp sensor, which would be a 10 minute fix.
Is there anyway to diagnose/confirm the fault? Nothing shows on my Hawkeye.

As @Feathers McGraw has shown above, the climate control has a stand alone self test built in.



Whether the climate control blows warm or cool will depend on a number of temperature inputs and settings to the system. When set to a particular temperature, the climate control will add warm or cool air to the cabin to maintain the interior temperature at the value set.

Thanks for the replies. It turned out to be a 15 minute fix. 10 minutes to try to remove the sensor, realise that even if I could get the top screw out, my chances of getting it back in again were vanishingly small, and 5 mins to speculate that the problem was fluff on the sensor, squirt brake cleaner through the grille and test the system. Works beautifully.