Sunload Sensor
WARNING: This page is about a different car, the 2018 Land Rover Discovery and 2017 Land Rover Discovery. However, it is still accessible from the selected car via links, so may be relevant.
The sunload sensor is mounted in the center of the instrument panel upper surface. The sensor contains a photoelectric cell, which provides the Automatic Temperature Control Module (ATCM) with an input of light intensity equating to the solar heating effect on the cabin.
The ATCM supplies the sunload sensor with a 5V reference voltage. The ATCM compensates for the solar heating effect by adjusting blower speed, air output temperature and air distribution to maintain the required cabin temperature.
NOTE:
On the 2 Zone manual system, there is no sunload sensor. There is a housing fitted into the location but no control electronics.