car air flow sensor

Today, let’s talk about the basic principle and inspection method of the air flow sensor.
The air flow meter is installed between the air filter element and the electronic throttle valve to accurately measure the amount of air entering the cylinder, and then convert the air intake data signal into a working voltage data signal and enter it into the electrical control system module, and the electrical control system module measures the ignition Advance the angle, control the injector to spray into the electronic throttle chamber (air intake), which is the best ratio (14.:7) to the intake air supply. At this stage, the air flow meters used in the car mainly include vane air flow meters, Lenny vortex air flow meters, vacuum pump speed ratio (liquid level sensor) air flow meters (intake branch pipe liquid level sensor), hotline air flow rate meter and heat pipe air flow meter. Among them, the vacuum pump speed ratio air flow meter is only the intake branch pipe liquid level sensor.
1: Vane air flow meter:
The vane air flow sensor is also known as a wing rotor or a suspended plate air flow sensor. The key consists of blades, sensors and terminals.
Schematic diagram of the internal structure
2: Heart-type air flow meter.
The frame diagram of the sensor of the central air flow meter.
Type 1 and 2 sensor inspection methods.
1. The motor vehicle detection starter motor of the air flow sensor is placed in the OFF position, and the wire connector of the air flow sensor is unplugged. Use a digital multimeter to measure the resistance of the power line side RF connector UC-E1 The working voltage should be 5V, otherwise the common fault of the power line or ECU should be protected or replaced.
2. Air flow sensor parts inspection:
The starter motor is located in the OFF position, unplug the air flow sensor wire connector, remove the air filter element connected to the air flow sensor air inlet, remove the sensor fixing anchor bolt, and remove the air flow sensor from the car engine. First, check whether the air flow sensor itself is cracked and whether the heart is open. Use a digital multimeter to measure the resistance between the terminals on the RF connector of the air flow sensor to see if everything is normal. If it is abnormal, the air flow sensor must be replaced. When accurately measuring the resistor in the middle of the total air flow data signal terminal (US-E1), you must move the heart slowly and observe the change of the resistance value of the digital multimeter.