Sensor, Sun: Operation

WARNING: This page is about a different car, the 2017 Jeep Cherokee. However, it is still accessible from the selected car via links, so may be relevant.

The Automatic Temperature Control (ATC) Dual Zone heating and A/C system uses two 0-5 volt sun sensors incorporated in one housing to balance the system in response to side-to-side variations of sun light intensity. As the sun light intensity increases, the resistance of the sun sensor increases, thereby lowering the signal voltage output to the Heating, Ventilation and Air Conditioning (HVAC) module. Passengers in sun and shadow require different functional settings because they experience very different temperatures. The sun sensor assembly provides data to the HVAC module to help determine proper mode and blend-air door positions and blower motor speeds. The sun sensors are not thermistor type sensors, but rather photo diodes. For this reason the sun sensors responds to sun light intensity rather than temperature. The sun sensor assembly is also used to sense day and night conditions for automatic headlight control, if equipped.

The sun sensor is diagnosed using a scan tool. Refer to HEATING & AIR CONDITIONING (ATC) DIAGNOSTIC CODE INDEX .

The sun sensor assembly cannot be adjusted or repaired and must be replaced if inoperative or damaged.