Sensor failure after cleaning throttle.

1, the failure of the computer power cord will make the performance of the automobile engine worse and the economy lower, so you should check the computer power cord before replacing the automobile computer. (The power cord should include the ground wire and be regarded as a complete power cord). 2. If the voltage signal of the oxygen sensor is higher than the standard value, it may be that the sensor is polluted, which will make the air-fuel ratio rich in many cases. 3. If the voltage signal of the oxygen sensor is lower than the standard value, it may be that the sensor is out of order, which will lead to the lean air-fuel ratio of the engine. 4, check the oxygen sensor must use digital multimeter or oscilloscope. 5. If the oxygen sensor heater is faulty, it may prolong the open-loop working time of the engine and increase fuel consumption. 6. Engine coolant temperature sensor can check its performance with digital meter or analog meter. 7. In some computer ECT circuits, an internal resistor is controlled to change the voltage on the sensor at a certain temperature of the engine. If the voltage at this time is abnormal during the measurement, it does not mean that the sensor is faulty. 8. Testing the engine coolant temperature sensor and the air temperature sensor can use exactly the same operating procedure. The only thing to note is that their temperature change curves are different, so there will be no same voltage signal at the same temperature. 9. When the throttle is opened and the voltage signal of the throttle position sensor is checked, the stability of the sensor can be checked by vibration with appropriate force. This method is very effective for virtual connection faults of some circuits. 10, many four-wire throttle position sensors include an idle position switch, which is used to provide the engine control unit with the working state information when the throttle is in the idle position. 1 1. In some cases, when the throttle is in the idle position, you can loosen the fixing screw of the throttle position sensor and rotate the sensor housing to adjust the voltage signal. 12. If the absolute pressure sensor of the intake manifold outputs a frequency signal, it can't be detected by a common multimeter. 13. Many intake manifold absolute pressure sensors output voltage signals converted from atmospheric pressure. This signal can be checked by turning on the ignition switch. (This method can only prove that the sensor can still work. If the output accuracy drops, this method can't be detected. ) 14. When checking the output voltage signal of the absolute pressure sensor of the intake manifold, there should be a certain degree of vacuum in the sensor. In most cases, it can be judged by detecting its output signal every 10 kPa. 15. When measuring the voltage signal of the vane-type intake air flow sensor, you can check when the vane of the sensor turns from fully closed to fully open, and observe the voltage value and continuity of the output signal. 16. Some intake air flow sensors with thermal resistors or hot wires are provided with voltage signals of different frequencies by the engine computer. This kind of sensor can only check its voltage with a multimeter that can test the frequency. 17. The voltage signal of the exhaust gas recirculation valve position sensor will change from 0.8V when the valve is closed to 4.5V when the valve is fully opened. 18, the computer uses the signal of the speed sensor to control the clutch of the torque converter, shift gears while driving, and collect data from the driving computer.