Twilight Sensor (ECC Only)
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2013 Volvo C70, 2012 Volvo C70, 2011 Volvo C70, 2010 Volvo C70, and 2009 Volvo C70. However, it is still accessible from the selected car via links, so may be relevant.
The twilight sensor consists of a photo diode powered from the central electronic module (CEM). The conductivity of the diode depends on the amount of light to which it is exposed.
The diode is under a diffusing lens which reduces the sensitivity of the photo diode to the angle of the light hitting it. Increased light intensity reduces the voltage over the photo diode.
The control module measures the voltage across the photo diode and converts the voltage to information which is then transmitted to other control modules via the controller area network (CAN).
The twilight sensor is located in the same holder as the sun sensor and alarm diode.
There are diagnostics for the twilight sensor.