From the Tech Support Archives: VW - No Heat when on "Vent" setting

Applies to the following Volkswagen vehicles: 

2005 > Jetta, 2009 > Jetta Sportwagon, 2006 > GTI/Rabbit, and 2007 > EOS

 

Customer concern is a lack of heat with heater controls  set on “Vent”. Heat appears to be normal with heater controls  set on “Floor”.

 

Check the Left Vent Temperature sensor (G191) for proper readings. Use Data Block 5, Field 1 for the "Vent" temperature sensor reading, and Data Block 5, Field 2 for the "Floor" temperature sensor reading. Move the heat selector to cold and see if the values change. The reading should be close to the outlet air temperature and will be displayed in Celsius.

 

The Left Vent Temperature sensor (G191) is located in the far left vent tube and can be accessed through the SC fuse panel cover.