WARNING: This page is about a different car, the 2010 Porsche Cayenne, 2009 Porsche Cayenne, and 2008 Porsche Cayenne. However, it is still accessible from the selected car via links, so may be relevant.
Information
Make sure that the vent hose -A- is not kinked or damaged. If in doubt, replace it.
The vent hose -A- must be inserted in the battery and in the battery box.