DTC 00768: Auxiliary Heater Core Temperature Sensor Circuit
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.
Check auxiliary heater core temperature sensor under value block. See READING MEASURING VALUE BLOCK under SYSTEM TESTS. If any DTCs for auxiliary evaporator temperature sensor exist, check connections between 6-pin splice behind fuse/relay panel to ground (located in CCM wiring harness). Check continuity between terminals No. 20 (Black/Brown wire) and No. 19 (Yellow wire) of CCM 28-pin harness connector "C". If continuity exists, check for short to ground. If short to ground does not exist, replace auxiliary heater core temperature sensor.