Detection method of crankshaft position sensor
At present, the commonly used crankshaft position sensors are mainly divided into three categories: magnetoelectric type, Hall type and photoelectric type. 1. The gap between the sensor and the target wheel should be checked first for magnetoelectric type and Hall type. 2. Magnetoelectric type can be used to detect its resistance with a resistance meter, and the resistance value is generally between several hundred and more than one thousand ohms, depending on the vehicle type. You can also start the engine and measure its voltage. The voltage should increase with the increase of engine speed. 3. The Hall sensor can test the power supply voltage first (note: it should be turned on when measuring), and then measure the grounding of the sensor. Finally, measure the signal. The signal voltage should be close to the reference voltage and 0 V. The Hall crankshaft position sensor has three wires, one is the power supply wire (providing the reference voltage), the other is the ground wire and the other is the signal wire. When the sensor works, the signal line will output a square wave signal, the amplitude of the square wave is close to the reference voltage, and the bottom of the square wave is close to 0 V. The higher the engine speed, the greater the frequency of the square wave.
Detection method of electromagnetic induction crankshaft position sensor
1. Measure the resistance of the electromagnetic induction crankshaft position sensor with a multimeter.
(l) Unplug the harness plug of the electromagnetic induction crankshaft position sensor.
(2) Measure the resistance between the two terminals of each induction coil in the harness socket of the electromagnetic induction crankshaft position sensor with a multimeter. This resistance is the resistance of the induction coil of the electromagnetic induction crankshaft position sensor. The resistance of the induction coil of the electromagnetic induction crankshaft position sensor of different types of EFI engines is not exactly the same, usually hundreds of ohms to thousands of ohms. If the measured resistance does not meet the standard, or the induction coil is short-circuited or open-circuited, it means that it is faulty and should be replaced.
2. Measure the output electric pulse of the electromagnetic induction crankshaft position sensor with a multimeter.
When measuring the electric pulse output by the electromagnetic induction position sensor with a multimeter, pointer multimeter should be used, and the multimeter selector switch should be set to the DC voltage position around Iv. When the sensor is in working state (i.e. when the rotor rotates), measure whether there is an output electric pulse between its two ends. The specific method is as follows:
(1) For the electromagnetic induction crankshaft position sensor or camshaft position sensor installed near the crankshaft pulley or camshaft, the engine motor can be used to drive the crankshaft to rotate, and the multimeter can be used to measure whether the sensor outputs electric pulses. If the multimeter pointer swings when the crankshaft rotates, it means that the sensor has electric pulse output and works normally; Otherwise, the sensor is faulty.
(2) For the electromagnetic induction crankshaft position sensor installed in the distributor, apart from the engine motor driving the crankshaft to rotate, you can also disassemble the distributor, rotate the distributor shaft by hand, and measure whether the sensor outputs electric pulses with a multimeter. If the multimeter pointer does not swing when rotating the distributor shaft, the sensor is faulty. Many models have two sets of electromagnetic induction crankshaft position sensors in the distributor, which can be confirmed by observing the structure of induction rotor or the number of induction coils in the distributor. These two groups of sensors are used to detect the signal that the first cylinder piston reaches the top dead center position of the compression stroke and the signal that each cylinder piston reaches the top dead center position of the compression stroke, so the output signals of these two groups of sensors should be measured separately (no matter which group of sensors has no output signal, it will affect the work).
3. Measure the output electric pulse waveform of electromagnetic induction position sensor with oscilloscope.
When measuring the waveform of the electric pulse output by the electromagnetic induction position sensor with an oscilloscope, the oscilloscope should be connected with the lead wire of the electromagnetic induction position sensor wiring harness to output the signal, and the measurement should be carried out under the working state of the electronic control device. For example, when measuring the electric pulse output by the crankshaft position sensor, it should be carried out when the engine is running; When measuring the electric pulse waveform output by the speed sensor, it should be carried out while the car is driving. The waveforms of electric pulses output by various electromagnetic induction position sensors are basically the same (Figure 3-33)-if there is abnormality, such as the pulse waveform is too gentle or intermittent, it indicates that the sensor is faulty.
After reading the article, I believe everyone has a certain understanding of the ignition baby in their car engine. Is it technical control? There are three types of crankshaft position sensors on the market. Bian Xiao found one of the most commonly used electromagnetic induction crankshaft position sensors to introduce to you. Look for the crankshaft position sensor according to your engine and see if there is any problem. In the future, if you go to maintain your car, you won't be afraid of being cheated by others. If the engine breaks down, it will be very troublesome to replace it.