Auxiliary Heater Core Temperature Sensor
WARNING: This page is about a different car, the 2003 Volkswagen EuroVan and 2002 Volkswagen EuroVan. However, it is still accessible from the selected car via links, so may be relevant.
Measures temperature of auxiliary evaporator for auxiliary blower speed and temperature regulation. If sensor malfunctions, CCM will ignore sensor and substitute a default temperature value of 108°F (42°C).