auto Oxygen sensor type According to the size of the detection range, the oxygen sensor can be divided into a narrow type oxygen sensor and a wide type oxygen sensor. Narrow oxygen sensors are mainly divided into commonly used zirconia oxygen sensors and titanium oxide oxygen sensors. Wide-type oxygen sensor, that is, wide-band oxygen sensor, can be called wide-area oxygen sensor and other names.
The auto oxygen sensor, which is an important sensing component in the EFI engine control system, is an indispensable and important part in controlling the engine to work within the ideal air-fuel ratio range during auto exhaust emission. Once the oxygen sensor fails, the computer of the electronic fuel injection system will not be able to obtain the information of the oxygen concentration in the exhaust pipe, so it will not be able to perform feedback control on the air-fuel ratio, which will increase the fuel consumption and exhaust pollution of the engine. Vibration and other failure phenomena:
The common factors that lead to the failure of the oxygen sensor are mainly as follows: (1) The aging of the sensor, a lot of carbon particles will be formed during the fuel process, these carbon particles may cause the protective layer on the surface of the oxygen sensor to peel off, and the high exhaust temperature will also cause Lead to accelerated aging or even failure of the sensor. (2) The sensor is poisoned to lead and silicon. The silicon dioxide produced by the combustion of leaded gasoline and silicon compounds contained in lubricating oil will cause a certain degree of mid-spring phenomenon to the oxygen sensor. (3) The carbon on the surface of the sensor, the addition of some external solvents or anti-sticking agents, etc. will cause the engine to burn gasoline insufficiently to produce carbon deposits. In addition, some impurities in the external environment may also cause deposition and blockage. It will affect the normal operation of the oxygen sensor. (4) Defective wire harness such as loose connector terminals, rust, uneven terminals, wire harness disconnection, virtual connection, etc., which cause the diagnostic instrument to display oxygen sensor signal faults and oxygen sensor heating faults, etc.; (5) Mechanical impacts such as flying stones cause sensor damage. (6) Moisture, condensed water or pollutants enter the sensor and cause the sensor to fail.
Oxygen sensor detection and troubleshooting
The first troubleshooting method (for wiring harnesses and connectors):
1. Check the oxygen sensor heating control wire (two white wires), signal wire (black) and signal ground wire (gray) for open circuit or short circuit. If so, replace the wire harness. Because the wiring harness failure will also report the oxygen sensor related failure.
2. Check whether the male and female terminals of the oxygen sensor harness connector are corroded and whether the terminals are level. If there are, you need to adjust the terminals, clean the terminals or replace the wiring harness, because the virtual connection of the wiring harness will also report the fault related to the oxygen sensor.
3. Check whether there are damaged pits on the surface of the sensor. If there is, it may be caused by mechanical damage to the sensor.
4. Press the outer sealing ring of the oxygen sensor and shake it close to the ear. If there is any abnormal sound, it means that the internal ceramic sensing element may be broken because of the failure caused by temperature shock or mechanical external force. The oxygen sensor is passively damaged. .
3. Use the engine diagnostic instrument to communicate with the ECU of the EFI system, and read the fault data in the ECU to make a judgment on the failure of the oxygen sensor.
