The mass airflow sensor measures the amount of air entering the combustion chamber. It is usually located between the air filter and the throttle body. The MAF sensor signal is used by the engine control module to calculate the amount of fuel needed for combustion. In winter, the air is denser hence more fuel is injected into the combustion chamber. If the engine gets warmer the fuel consumption will be less.
A mass air flow sensor comes with different numbers of wires. Knowing the wiring diagram of the mass air flow sensor is important for testing the sensor or doing other work. This information is important to know when troubleshooting or replacing an oxygen sensor. With this knowledge, you will be able to save time and money.
In this powerful article, you will quickly learn 3, 4, and 5 wire mass air flow sensor wiring diagrams.
Mass Air Flow Sensor Wiring Diagram
The wiring diagram of the mass air flow (MAF) sensor is different according to the year, make, and model. The manufacturer designs the wiring diagram of the mass air flow sensor according to the need and demand.
In this powerful guide, we will be more general than specific. I mean, I am giving you a general idea of how the mass air flow sensor wiring is designed.
For your specific make and model, you should check your car owner’s manual. The color of wires will vary and are color-coded depending upon the brand of the sensor.
3 Wire Mass Air Flow Sensor Wiring Diagram
A three-wire MAF sensor consists of three wires, power, ground, and signal, which are listed below.
- Hot Power Wire (Reference voltage comes from the ECU)
- Ground Wire
- Signal Wire (Gives Signals to the ECU)
The hot wire is a feed power source that is taken from the car computer (ECU). This is a reference voltage, which means the car ECU Powers the MAF sensor through this wire.
The ground wire is also taken from the ECU. This ground wire gives earth to the MAF sensor. A third wire is a signal wire means the MAF sensor gives the input (signal) to the car ECU through this wire.
4 Pin Mass Air Flow Sensor Wiring Diagram
A four-wire mass air flow sensor has four wires.
- 12 Volt Feed Positive Power
- MAF Wire Ground
- MAF Signal ground
- MAF Signal
A 4-wire mass air flow sensor has a 12-volt positive power source, which is connected to the fuse box’s fuse and relay. The MAF Signal Wire goes to the car ECU. The signal wire means the MAF sensor sends the signal (Output Voltage) to the ECU.
A four-wire Mass air flow sensor has two separate grounds. One ground is for the hot feed wire. This wire is earthed somewhere in the chassis. And the second one is for the MAF signal circuit. The MAF signal circuit is given a separate ground, which goes to the car ECU.
The MAF sensor’s signal circuit is placed in the MAF sensor, which calculates how much current flows to the sensor and converts that current to the voltage, and sends it to the car ECU through the MAF signal wire. This signal’s circuit is given a separate ground.
5 Wire Mass Air Flow Sensor Wiring Diagram
A five-wire MAF sensor consists of five wires.
- MAF Power
- MAF Ground
- MAF Signal
- Air Temperature Signal
- Air Temperature Reference Volt
A MAF sensor power wire gives a positive current to the MAF sensor. Usually, this hot power wire is taken from the fuse box’s fuse and relay. The ground wire gives earth to the MAF sensor and is usually taken from PCM, or sometimes, it is earthed somewhere in the chassis.
The MAF’s signal wire gives the signal to the ECU. In mass air flow there is an air intake temperature (IAT) sensor integrated into the MAF sensor, which has two additional wires, a power, and a signal wire.
A power wire comes from the ECU, which is usually a 5-volt reference voltage. And a signal wire goes to the ECU back, informing the ECU about the state of temperature of the ambient air.
This is an Info
A reference volt is a constant voltage given by the ECU to the electronic component in the car, which does not change its value due to variations in temperature, loading on the device, or passage of time.
The number of wires on an airflow sensor depends upon the make and model of the sensor. Some sensors have three wires, others have four, and still others have five. So, it really depends upon the specific sensor in question.
There is a possibility that the mass air flow sensor could be causing your car to stall. The mass air flow sensor measures the amount of air that is entering the engine. If there is not enough air, then the engine will not run properly and can stall.