Understanding the expected voltage ranges at each pin is vital. For instance, the THW pin should read approximately 2.5V at 68°F (20°C) and drop below 0.5V when the engine is hot. If a technician measures 5V on the THW pin at operating temperature, the pinout tells them either the sensor is open-circuit or the signal wire is shorted to the reference voltage line (VCC).
Without the correct pinout:
Receives coolant temperature data via a built-in thermistor. Intake Air Temp toyota 4afe ecu pinout