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The heated oxygen sensor (HO2S)
Heated
oxygen sensor detects an oxygen concentration in the exhaust gas and converts a voltage supplied to the engine control unit ECM. On vehicles with an engine of 2.0 l DOHC
the output voltage of the sensor is equal to 1 if the fuel mixture is richer in relation to the theoretical and the voltage is 0 V if the fuel mixture is poorer (higher concentration of oxygen in the exhaust gas). On vehicles with engine 2.5 liters V 6
the output voltage of the sensor is equal to 0 if the fuel mixture is richer in relation to the theoretical and the voltage is 5 V when fuel mixture poorer (higher concentration of oxygen in the exhaust gas). In order to complete combustion of the combustible mixture and the exhaust gases no harmful substance, 14.7 parts by weight of the air shall have to 1 part of fuel (theoretical ratio). Based on these data, the engine control unit changes the opening of the injectors and the fuel ratio in toplivnovozdushnoy mixture. The oxygen sensor is equipped with a heater that maintains a temperature sensor within a certain range when the engine under all operating conditions. Maintaining a specific temperature sensor enables the system to quickly engage in work and to work in an idling mode. Checking (2.0 L DOHC) |  | Before testing the engine to warm up until the coolant temperature is equal to 80-95 ?� C. Accurate digital voltmeter to measure the output voltage of the sensor. |
 | 1. Unplug the connector from the oxygen sensor and connect a voltmeter to the oxygen sensor connector. |
2. By changing the frequency of rotation of the crankshaft of the engine, measure the oxygen sensor output voltage, which in the acceleration mode should be about 0.6 V. If the output voltage of the sensor is not correct, replace the sensor. Torque: 40-50 N ??? m |
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Verification (2.5L V6) | | Before testing the engine to warm up until the coolant temperature is equal to 80-95 ?� C. |
 | 1. connector terminals 3 and 4 post battery voltage. | When voltage is applied, be careful not to mix and close the connector terminals. |
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2. Connect a digital voltmeter between terminals 1 and 2.
3. By changing the frequency of rotation of the crankshaft of the engine, measure the oxygen sensor output voltage, which in the acceleration mode should be about 4.5 V.
4. If the sensor output voltage is not correct, replace the sensor. Torque: 40-50 N ??? m |
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