939010270 - 5040DC Check sunlight sensor operation (Automatic Air Conditioning)

Use a multimeter to check that with the ignition key on, a voltage is present between Pins 1 and 4 and between Pins 3 and 4 of the solar radiation sensor that is proportioal to the heat energy present on the windscreen analysed by the sensor photodiodes: there should be a signal of less than 5 Volt (between 4.5 V - minimum solar rays - and 0.5 V - maximum solar rays).    See K090 SOLAR SENSORIf there is a problem, using a multimeter and disconnecting the sensor, check with the ignition key in the ON position that the voltage between pins 1 and 4 and between pins 3 and 4 of the sensor supply connector is about 5 Volt.    See K090 SOLAR SENSOR