What is the working principle of the intake pressure sensor?

[MacVincent]

The working principle of the intake pressure sensor: It detects the changes in the absolute pressure in the intake manifold based on the engine speed and load, then converts it into a signal voltage and sends it to the engine control unit. The engine control unit uses this signal voltage to determine the basic fuel injection quantity. There are various types of intake pressure sensors, including piezoresistive and capacitive types. Due to its fast response time, high detection accuracy, small size, and flexible installation, the piezoresistive type is widely used in D-type injection systems. The pressure sensor measures pressure using a pressure chip, which is the core component of the sensor.

[VanessaAnn]

The working principle of the intake pressure sensor is as follows: It is installed on the engine intake manifold and specifically measures the air pressure there. At its core is a silicon diaphragm that deforms when pressure increases or decreases, causing the internal resistance value to change accordingly. This resistance change is converted into a voltage signal and sent to the Engine Control Unit (ECU). The ECU uses this signal to estimate the amount of air entering the engine and then precisely adjusts the fuel injection quantity to ensure the proper air-fuel ratio. If the pressure is high, such as during acceleration, the ECU increases fuel injection; conversely, it decreases fuel injection during deceleration. This device is quite crucial, especially in turbocharged vehicles where pressure fluctuations are greater, requiring the sensor to respond quickly to avoid engine shuddering or excessive fuel consumption. For regular maintenance, periodically checking whether the sensor connector is loose can prevent inaccurate readings caused by dirt. Overall, it acts like a guardian angel, silently ensuring the engine runs smoothly.

[DelHope]

In the engine management system, the intake pressure sensor plays a crucial role. Its working principle is based on a pressure-sensitive element, typically a piezoresistive material, which changes resistance in response to variations in intake manifold pressure. This change is converted into a 0-5V voltage signal and transmitted to the ECU. The ECU uses this data, combined with other parameters like temperature, to calculate air flow and fine-tune fuel injection and ignition timing. If the pressure is low, indicating less air, the ECU reduces fuel injection; higher pressure leads to increased fuel injection. This ensures the engine operates efficiently under various conditions, preventing issues like unstable idling or soaring fuel consumption. While driving, you rarely notice it, but if it malfunctions, the car may exhibit power loss or flash warning lights. It's recommended to have a technician inspect it every 50,000 kilometers to maintain system health and prolong the vehicle's lifespan.

[StephanieFitz]

If the intake pressure sensor malfunctions, it will directly affect engine performance. Its working principle is that when the pressure in the intake manifold changes, the resistance element inside the sensor deforms, generating varying voltage signals sent to the ECU. The ECU uses this data to adjust the air-fuel ratio. If faulty, distorted signals cause the ECU to misjudge air volume, leading to inaccurate fuel injection, which may result in idle shaking, acceleration lag, increased fuel consumption, or the engine warning light illuminating. In extreme cases, such as high-speed driving, it may cause engine stalling. Common causes include connector contamination or voltage instability. Regular engine bay cleaning can help prevent these issues.

[NoahLynn]

DIY handling of the intake pressure sensor is quite convenient. Its working principle involves an internal pressure-sensitive diaphragm, where changes in manifold pressure cause resistance variations, outputting voltage signals to the ECU. To inspect it, first locate its position on the intake manifold, unplug the connector, and check for rust or looseness. Clean it and plug it back in. If the car has unstable idling, use a multimeter to measure the voltage: normal idle should be 0.5-1V, and it should rise above 1.5V when the throttle is pressed. A fixed value or large fluctuations indicate a fault. A simple test method: start the engine and unplug the connector; if symptoms improve, the sensor should be replaced. For routine maintenance, keep the area around the sensor clean to extend its lifespan.