Volkswagen Santana air flow meter how to check with a multimeter

1. Introduction to air flow meter.

The role of the air flow meter.

The air flow meter measures the amount of fresh air entering the engine intake manifold and the intake air temperature, and the ECU uses this information to make injection corrections, smoke limits, and EGR opening control.

2.Installation location.

The sensor is mounted on the engine intake duct and at the rear end of the air filter.

3.How it works.

The principle of an air flow meter.

The air flow sensor is to integrate some electronic components on a ceramic substrate, when the engine is working normally, the diaphragm is first heated, and the fresh air flows through the sensor will take away part of the heat, at this time the ECU will control the Wheatstone bridge on the diaphragm to supplement the diaphragm, which will cause a change in the electrical signal, when the signal is transmitted to the ECU, the ECU will calculate the air intake according to this change.

The principle of the air temperature sensor.

The inlet air temperature sensor is a negative temperature coefficient resistor, when the inlet air temperature changes, the resistance value of the resistor will change, causing a change in the signal voltage at the ECU terminal, and the ECU calculates the inlet air temperature based on this change.

Determination of the direction of the airflow.

There is a same temperature resistance at both ends of the hot film of the air flow meter, and when the air flow flows through the hot film, it will take away part of the heat, so the temperature at the front end of the hot film is lower than the temperature at the rear end, and the ECU judges the direction of the air flow according to this signal!

4.Wiring diagram of an air flow meter.

5.Control policy.

The ECU will monitor the working condition of the air flow meter at all times, and when the ECU judges that the air flow meter is faulty, it will take corresponding control, as follows.

The engine mil light is lit, the EGR system is withdrawn from work, and the exhaust gases will no longer participate in the system work;

The engine speed will be limited to a certain speed, and the power will be limited;

When the air flow meter fails, the engine start is not affected and can be started normally;

Second, the detection of air flow meter:

Fault codes related to air flow meters.

Hello, the air flow meter is a chipset, and the multimeter can't detect it.

Summary. The Jotana 30000 Air Flow Meter pins are defined as follows:1

VCC: positive power supply, connected to 5V power supply; 2. gnd：

Negative pole of power supply, grounded; 3.out: output signal, connected to analog input module; 4.

LED: indicator light, connected to 5V power supply; 5. adj：

Adjustment, grounding; 6.VREF: reference voltage, connected to 5V power supply; 7.

GND: negative of power supply, grounded; 8. vcc：

The positive pole of the power supply is connected to the 5V power supply.

The Jotana 30000 Air Flow Meter pins are defined as follows:1 vcc：

The positive pole of the power supply is connected to the 5V power supply. 2.GND: negative of power supply, grounded; 3.

out: output signal, connected to analog input module; 4. led：

indicator light, connected to 5V power supply; 5.adj: adjustment, grounding answer; 6.

Negative pole of power supply, grounded; 8.VCC: The positive pole of the ruler is connected to the 5V power supply.

Fellow, I really didn't understand, I can be more specific.

The Routon 30000 air flow meter pins are defined as follows:1 vcc：

The positive pole of the power supply is connected to the 5V power supply. 2.GND: negative of power supply, grounded; 3.

out: output signal, connected to analog input module; 4. nc：

Useless, not wired. If there is a problem when using the Routon 30000 air flow meter, it may be due to the following reasons:1

Unstable power supply voltage: The unstable power supply voltage will affect the accuracy of the air flow meter, and the power supply voltage should be stable; 2.Poor connection:

The poor connection of the air flow meter will affect the measurement accuracy, and the connection should be ensured to be good; 3.Incorrect measurement range: The measurement range of the air lift finch flow meter should be set according to the actual situation to ensure the measurement accuracy.

Solution: Quietly trapped 1Ensure that the power supply voltage is stable; 2.

Make sure the connection is good; 3.Set the measurement range according to the actual situation. Personal Tips:

When using the Routon 30000 air flow meter, you should ensure that the power supply voltage is stable, the connection is good, and the measurement range should be set according to the actual situation to ensure the measurement accuracy as early as possible.

The air flow meter is a very important sensing signal in the electronic injection car, which is the same as the crankshaft position sensor signal and is the main signal for the car to start. In other words, the car cannot be started without this signal (some low-end cars can start, but after starting, the car will be unstable, swimming, unable to speed up, high fuel consumption, exhaust emissions exceed the standard, etc.).

The air flow meter is generally installed behind the air filter to detect the air volume, air temperature and air density, etc., and the signals collected by this sensor are transmitted to the engine computer (ECU) of the car, which decides how much gasoline to inject according to this signal and other signals to provide the car with the best and most reasonable air-fuel ratio (mixture of air and gasoline).

If this sensor malfunctions in the car, the engine indicator on the gauge will illuminate. You can first go to a regular enterprise to clear the fault code, if it can be cleared and there is no longer a problem, you can not replace it. If the inspection determines that the sensor itself is faulty, it can only be replaced.

It is installed in the intake duct and measures the amount of air entering the engine.