What Is an Air Intake Sensor and How It Works?

What Is an Air Intake Sensor and How It Works?

The air intake sensor is the component that is responsible for monitoring air temperature entering the engine. This is important for the powertrain control module(PCM), which is the engine’s computer. This allows the PCM to determine the air density so that it can set a balance air/fuel ratio. As you already know colder air is denser than hotter air.

This means that colder air requires more fuel to burn, so this is a very big factor that needs to be determined beforehand. So this change is brought on by PCM by controlling the length of the injector impulses.

In pre-1995 models, it had different names. These were often called Air Charge Temperature (ACT) sensor, a Vane Air Temperature (VAT) sensor, a Manifold Charging Temperature (MCT) sensor, a Manifold Air Temperature (MAT) sensor or a Charge Temperature Sensor (CTS).

How The Air Intake Sensor Works?

The air intake sensor is usually mounted on the intake manifold. This means that the tip is exposed to air entering the engine. With engines that have mass airflow sensors to check the volume of air flowing into the engine, you may seem another temperature sensor. You can see more than one temperature sensor in engines that have split intake manifolds. This means that split intake manifold cars with a V6 or V8 engine may have more than one Air Intake Sensor.

The air intake sensor has a built-in thermistor. This means that the electrical resistance changes with temperature. The PCM has a reference voltage, which is usually 5 volts. Then it receives the signal back and then analyzes to find out the estimated temperature. In most air intake systems, the sensors are built with negative temperature coefficient thermistors.

What this means is that the lower the temperature the more resistance the thermistor provides.

However, there are some sensors with the opposite thermistors. Those thermistors are known as positive temperature coefficient thermistors. Here the resistance increases with temperature increase. The PCM reads the change in voltage caused by the difference in resistance and then matching it with the reference temperature it determines the air temperature.

For older models, it might be a bit different. In cold temperatures, the signal from the air intake sensor may be used to turn on the cold start injector. The sensor is also used to delay the EGR valve opening until the engine warms up in older models.

Air intake sensors are also used in your car’s automatic climate control system. There is usually more than one sensor present in the car. The automatic climate control system has its own air intake sensor. This is used to measure the temperature outside the car and also inside the passenger compartment. Sensors for the climate control systems are placed outside the engine compartment so engine heat does not affect it. You can find the air intake sensor in the behind the grille or in the cowl at the base of your car’s windshield. These work exactly like the air intake sensors in the engine, while they may use infrared sensors instead of thermistors.

Conclusion So there you go, this is what an air intake sensor is and how it works. This is a vital component of the air intake system and you can find kits to restore them online. Make sure you take a look at the owner’s manual or consult an expert before you go into making changes on your own.