Front Sun Sensor

Front Sun Sensor

Description






• Typical sun sensor assembly shown.

The automatic temperature control HVAC system uses a sun sensor assembly (1) to measure sun light intensity. Three variants of the sun sensor are used, depending on how the vehicle is equipped. A twilight sensor (optional with three zone manual controls for automatic headlamps), left and right sun sensor for ATC HVAC system (2), and a combination twilight and sun sensor for ATC with automatic head lamps. The sun sensor assembly is mounted to the instrument panel and has a clear lens (3) that protrudes through the defroster grille. The wire harness receptacle (4) connects the sun sensor to the vehicle electrical system through a wire lead and connector of the instrument panel wire harness.

Operation

The ATC dual and three-zone HVAC systems use two sun sensors to balance the system in response to side-to-side variations in sun light intensity. Passengers in sun and shadow require different functional settings because they experience very different temperatures. The sun sensor assembly provides data to the A/C heater control 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.

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