Volkswagen T5 - Problem of active cooling car windows fog up | HELLA

Problem of active cooling car windows fog up

In the VW T5 vehicle type, model year 2004, the problem of fogged windows may be caused by a faulty evaluation function of the air quality sensor.

Air quality sensor (figure).

The built-in evaluation electronics in the sensor module responds to changes in the conductivity of the sensor.

Due to the design, the function or the evaluation of the air quality sensor may be affected by the influence of spray or drip water in this type of vehicle. (The air quality sensor is located below the windshield in the region of the fresh air intake.)

Solution:

Check the function of the air quality sensor

Check the fuse 22

Install a spray and drip water deflector for the sensor.

Additional information for service:

According to information from the manufacturer, the air quality sensor is not subject to wear under normal conditions.

The combfilter (interior filter) should be replaced at service intervals.