What are the main reasons for Porsche's driving light control malfunction?

Fault setting: The daytime running light function may have been turned off in the vehicle settings. You can adjust the headlight switch to automatic mode, so that the headlights will automatically turn on or off according to the ambient light.

Fuse blown: The fuse of the daytime running lights may be blown. If the fuse is damaged, it usually manifests as both sides of the lights turning off simultaneously. If only one side of the light is not on, the fuse may not be the problem.

Wiring harness fault: Check the wiring harness connection between the headlight control module and the daytime running lights. The wiring harness issue requires replacement.

Malfunction of the guiding ring drive: Loose plugs or poor contact can also cause this problem. Suggest going to a repair shop for professional maintenance. ‌23

Quality issues with light bulbs: Quality issues with daytime running light bulbs may also cause the lights to turn off. The quality of the bulb filament is poor. As the temperature increases, the resistance increases and the working current decreases, causing the daytime running light to turn off. Consider replacing high-quality light bulbs to solve the problem.