200 Quattro 20V Sedan L5-2226cc 2.22L DOHC Turbo (3B) (1991)
Coolant Temperature Sensor / Switch HVAC: Locations
Some models will have a coolant temperature sensor on the small coolant hose between the cylinder head and the heat exchanger. On vehicles without
this sensor, view the A/C control head. Channel 6 will display a code of 255 (open circuit).