I am very glad to see this discussion. I have noticed this and was told by the local Porsche dealer that it was like that on all of the Cayennes. Not sure why it cant be fixed. I have tried various things - driving with headlight switch off, shining a light on the sensor in the speedometer bezel, resetting the PCM to factory default. Nothing has worked.

 

The auto day/night function does not work on all Canadian Cayennes, and Porsche chose to ignore the issue. The same function works fine on my Panamera though.

 

why not to change country with PIWIS at dealer? if only Canada affected seems like changing coding will help...

 

According to Porsche Canada and my local dealer a fix is now available. Apparently, the PCM software had a problem in that it recognised the daytime running lights as headlights and would not allow the switch-over. It would only allow the daytime mode if the PCM was set to daytime, thereby overriding the DRL. This has been corrected as of an August 2015 PCM update available at your Porsche dealer.

 

This has been fixed with a software update. Works perfectly now.