Fig. 85 Heat-reflective windshield with communications window (blue shaded area).
Windshields made of insulating glass have a transparent metallic infrared-reflecting coating. There is an uncoated area (communications window) just above the inside rearview mirror ⇒ Fig. 85 . This serves as a communications window for transmitting signals to and from electronic components and accessories.
The uncoated area must not be blocked on the inside or outside or covered with stickers because this can cause the electronic components to malfunction.
Volkswagen Tiguan Service and Repair Manual > Refrigerant R134a Servicing: Concerns
Possible Refrigerant Circuit Concerns
Test Requirements
Note
The A/C system is functioning correctly when the air flowing from the
instrument panel vents has a temperature of 70C
or lower.
Setting on Climatronic "LO".
Setting on A/C system "AC" on; "max"; "cold".
The A/C system OBD cannot f ...