What sensors are used in the structure and working principle of the automatic gearbox?

Adjustment of the throttle position sensor Improper adjustment of the throttle position sensor will affect the normal operation of the electronically controlled automatic transmission, and even make the fault warning lamp light up, thus generating the fault code of the throttle position sensor. The adjustment method is as follows: a. Loosen the two fixing screws of the throttle position sensor. B insert a thickness gauge with a thickness of 0.50mm between the throttle rocker arm and the limit screw, and measure the continuity of the idle switch with a multimeter (fig. 1-74). Figure 1-74 Adjustment of the throttle position sensor C. Turn the throttle position sensor in the throttle closing direction, disconnect the contact of the idle switch, and then slowly turn the throttle position sensor in the throttle opening direction until the idle switch is closed. Tighten the two fixing screws of the throttle position sensor. C insert thickness gauges of 0.40mm and 0.65mm between the throttle limit screw and the throttle rocker arm respectively, and measure the conduction of the idle switch at the same time. When the thickness gauge is 0.40mm, turn on the idle switch; When the thickness gauge is 0.65mm, the idle switch should be turned off. Otherwise, the throttle position sensor should be readjusted. (2) Inspection and maintenance of speed sensor and input shaft speed sensor The structure and working principle of speed sensor and input shaft speed sensor are the same, and their inspection methods are the same, that is, various measurement methods judge whether their working performance is normal or not. ① Measurement of induction coil resistance of speed sensor or input shaft speed sensor: a. Unplug the wire harness plug of speed sensor or input shaft speed sensor. B use a multimeter to measure the resistance between two terminals of the speed sensor or the input shaft speed sensor (fig. 1-75). The resistance of this induction coil of automatic transmission of different models is not exactly the same, usually hundreds of ohms to thousands of ohms. Figure 1-75 Measurement of induction coil resistance of speed sensor If the induction coil is short-circuited, open-circuited or the resistance value does not meet the standard, the sensor should be replaced. ② Measurement of output pulse of speed sensor or input shaft speed sensor A. When measuring the output pulse of speed sensor, jack can be used to jack up the driving wheel on one side of the car, so that the joystick is in neutral position, and the suspended driving wheel can be rotated by hand. At the same time, use a multimeter to measure whether there is pulse induced voltage between the two terminals of the speed sensor. When measuring, turn the multimeter selector switch to the DC voltage blocking position or resistance off position below1v. If the multimeter pointer swings when the wheel is turned, it means that the sensor has output pulse and works normally; Otherwise, replace the sensor. B. When measuring the output pulse of the input shaft speed sensor, remove the sensor and quickly approach or leave the sensor with iron bars or magnets (Figure 1-76). At the same time, use a multimeter to measure whether there is a pulse induced voltage between the two ends of the sensor. If there is no induced voltage or the induced voltage is weak, the sensor is faulty and should be replaced. Figure 1-76 Measurement of output pulse of input shaft speed sensor (3) Maintenance of water temperature sensor and hydraulic oil temperature sensor are both semiconductor thermistors, and the maintenance method is the same. ① Remove the water temperature sensor or hydraulic oil temperature sensor. ② Put the sensor into a beaker filled with water, heat the water in the cup, and measure the resistance between the two ends of the sensor at different temperatures (Figure 1-77). Figure 1-77 Detection of water temperature sensor and hydraulic oil temperature sensor ③ Compare the measured resistance value with the standard value. If it does not meet the standard, replace the sensor. (4) Maintenance of the gear switch ① Detection of the gear switch The detection method of the gear switch is as follows: a. Lift the car with a hoist. B remove the connecting rod connected between the rocker arm of the manual valve of the automatic transmission and the operating lever. C. unplug the line speed plug of the gear switch. D move the rocker arm of the manual valve to all gears, and measure the continuity between the jacks in the gear switch harness socket with a multimeter. Compare the measurement results with the standard. If there is any difference, the gear switch should be readjusted. ② Shift the gear switch A. Remove the connecting rod between the rocker arm of the manual valve and the joystick. B loosen the lock nut on the rocker shaft of the manual valve and remove the rocker arm of the manual valve. C loosen the fixing bolts of the gear switch and remove the gear switch. D install the new gear switch in the reverse order of removal. E readjust the gear switch according to the specified procedure. (5) Maintenance of the switch solenoid valve The following methods can be used for maintenance of the switch solenoid valve such as the shift solenoid valve of the electronic automatic transmission. ① On-board inspection of switch solenoid valve A. Lift the car with a hoist. B. remove the oil pan of automatic transmission. Pull off wire harness plug for solenoid valve. Measure the resistance of solenoid valve coil with multimeter. The resistance of the solenoid valve coil of automatic transmission switch is generally (10 ~ 30)ω. If the electromagnetic coil is short-circuited, open-circuited or the resistance value does not meet the standard, it should be replaced. E. Add 12V power supply to the solenoid valve coil, and the "click" sound of the solenoid valve should be heard at this time; Otherwise, the valve core is stuck and the solenoid valve should be replaced. (2) Performance test of the switch solenoid valve The performance test method of the switch solenoid valve is as follows: a. Remove the solenoid valve. B. blow compressed air into the oil inlet of the solenoid valve. C. When the solenoid valve coil is not connected to the power supply, there should be no ventilation between the oil inlet and the oil outlet; Otherwise, the solenoid valve will be damaged and should be replaced. D. After the power supply is connected, the oil inlet hole and the oil drain hole should be connected; Otherwise, the solenoid valve will be damaged and should be replaced. (6) Maintenance of Pulse Linear Solenoid Valve The following methods can be used for maintenance of pulse linear solenoid valves such as electronic control automatic transmission oil pressure solenoid valve. ① On-board inspection of pulse linear solenoid valve A. Lift the car with a hoist. B. remove the oil pan of automatic transmission. Pull off wire harness plug for solenoid valve. Measure the resistance value of solenoid valve coil with multimeter. The coil resistance of pulse linear solenoid valve is small, generally (2 ~ 6)ω. If the solenoid is short-circuited, open-circuited, or the resistance value does not meet the standard, the solenoid valve should be replaced. ② Performance test of pulse linear solenoid valve The performance test method of pulse linear solenoid valve is as follows: a. Remove the pulse linear solenoid valve. B connect the battery power supply in series with a bulb of (8 ~ 10) W, and then connect it with the solenoid valve coil (the coil resistance of the pulse linear solenoid valve is too small to be directly connected with the power supply of 12V, otherwise it will burn out the solenoid valve coil). C. When power is on, the valve core of the solenoid valve should extend outwards; When power is cut off, the spool of the solenoid valve should be retracted inward. If it is abnormal, the solenoid valve is damaged and should be replaced. Another test method of pulse linear solenoid valve is to use adjustable power supply. The method is as follows: Connect the adjustable power supply with the solenoid valve coil. Adjust the power supply voltage and observe the movement of the valve core. When the voltage rises gradually, the valve core should move outward accordingly; When the voltage gradually decreases, the valve core should move inward accordingly. Otherwise, the solenoid valve will be damaged and should be replaced. Pay attention to keep the power supply current below 1A during inspection.