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SENSOR SIGNAL DELAY FUNCTION

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• Sometimes signals received from sensors will indicate abnormal readings. For example, intermittent or obstructed sunlight (when the vehicle is travelling on city streets or through highway tunnels) causes the sensor signals to be abnormal. When the vehicle is parked and the doors are opened/closed, sunlight intensity, ambient temperature, and cabin temperature signals may be interrupted or may vary suddenly and extremely due to heat radiation from the road. If control is carried out faithfully according to the signals input by the sensors, conditions in the passenger compartment may become uncomfortable and control will not be smooth. The climate control unit delays the input signals for sunlight intensity, ambient temperature, and cabin temperature. It then takes an average value of the readings it receives so that control remains stable, as shown below.
• In winter, once the engine is stopped and then restarted and the temperature around the engine remains high, the ambient temperature sensor will detect the engine heat, therefore, the system controls do not operate according to the actual ambient temperature. To prevent this from happening, each control operates based on the ambient temperature data stored in the climate control unit prior to the engine being stopped, as long as the engine coolant temperature is 55 °C {131 °F} or above when the engine is restarted.

1 | Sunlight intensity delay (example)
2 | Actual sunlight intensity
3 | Sunlight intensity input
4 | Time
5 | Ambient temperature delay (example)
6 | Actual ambient temperature
7 | Ambient temperature input
8 | Cabin temperature delay (example)
9 | Actual cabin temperature
10 | Cabin temperature input