Using an inlet air temperature sensor allows fuel and ignition corrections to be made for changes in the temperature of the air entering the engine. The air temperature sensor must be set-up to most accurately measure the temperature of the air entering the engines combustion chambers. On a naturally aspirated engine this normally means any position between the air filter and inlet manifold. However, on a turbocharged/supercharged engine the sensor must be placed AFTER turbocharger and any inter-cooler.
On most applications (both naturally aspirated and turbocharged) the recommended mounting position is in the inlet pipe just before the throttle plate. The sensor may also be placed in a section of the inlet manifold that is subject to high airflow. However, in some applications the inlet manifold may get very hot and heat soak the sensor causing a reading that is not representative of the air entering the combustion chambers.
It is very important on a turbocharged/supercharged engine that the air temperature sensor can react fast enough to track the rapidly changing temperature. For this reason, an open element sensor is required. The recommended sensor is a Bosch 0 280 130 085. On naturally aspirated engines this sensor may be substituted for a 0 280 130 039, which is cheaper and easier to fit.
G4X ECUs are designed to measure the temperature using a thermistor sensor. These sensors have a resistance that changes with temperature and are commonly used in automotive applications. When wiring thermistor sensors the polarity is NOT important. The Inlet Temperature Sensor must be connected to the Sensor Ground (green) wire and an Analog Temp wire.
G4X ECUs are compatible with any NTC or PTC thermistor sensors. The default calibration is for either of the Bosch sensors listed above. In order to use a sensor with a different calibration you will need to know how the sensor’s resistance changes with temperature and enter this information into the ECU via PCLink Tuning Software. Note that most commonly used sensors calibrations are available by selecting them in PCLink Tuning Software.