This warning light illuminates :
Hyundai Sonata LF 2014-2019 Service Manual: Timing Chain Components and Components Location
Components
1. Timing chain2. Timing chain guide3. Timing chain arm4. Timing chain auto tensioner
...
Hyundai Sonata LF 2014-2019 Service Manual: Photo Sensor Description and Operation
Description
The photo sensor is located at the center of the defrost nozzles.
The photo sensor contains a photovoltaic (sensitive to
sunlight) diode. The solar radiation received by its light receiving
portion, generates an electromotive force in proportion to the amount of
radiation rece ...