AIR Charge Temp Sensor Replaces: Mercruiser 805223T, Volvo 3854527 Fits: Mercruiser / Volvo 4.3L, 5.0L The Air Charge Temperature Sensor (ACTS) a thermistor sensor that inputs the temperature of the incoming air stream in the air filter or intake manifold to the computer. It can be located in the intake manifold (EFI systems) or the air cleaner.