7.2.13. The sensor of content of oxygen in the fulfilled gases
Oxygen sensor
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1. Seat socket
2. Socket of the secondary sensor
3. Cover
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4. Collar
5. First sensor |
The sensor of oxygen is intended for formation of a signal on the basis of which the computer determines the content of oxygen in exhaust gases and supports stoichiometric composition of gas mixture (14,7 parts of air to 1 part of gasoline) due to change of duration of injection of fuel. The signal of low level (0,1 B) from the sensor corresponds to the grown poor mix, and a signal of high level (0,9 B) – the enriched mix.
On the considered cars 2 sensors of oxygen – on an entrance and an exit of catalytic converter are installed. If temperature of the sensor is below 340 °C, then the signal from the sensor is absent and before warming up of the engine system the sensor – the computer works in the mode of the opened cycle. If after warming up of the engine the signal does not exceed 0,45 B at turns higher than 1500 rpm, then the mode of the opened cycle remains, and for processing instead of a signal from the sensor the data by default brought in memory of the computer are used.
Prevention
When checking the sensor it is forbidden to disconnect from it the flexible conductor, to overwind conducting, and also to subject the sensor to sharp mechanical influences. It is forbidden to apply solvents to cleaning of the sensor.
Check
| PERFORMANCE ORDER |
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1. Insert needle probes of the voltmeter into the sensor socket, on conclusions 3 (the positive plug of the voltmeter) and 4 (the negative plug) – in the 4-cylinder engine. Lift a car front. For access to the socket of the second sensor it is required to remove a front seat. |
| 2. Start the engine and you monitor indications of the voltmeter in process of warming up of the engine. On the cold engine tension has to be 0,1–0,2 Century. On the heated-up engine tension has to begin to fluctuate within 0,1-0,9 B (the mode of the closed cycle joins). If the mode of the closed cycle does not join, or joins with big delay, then replace the sensor. |
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3. Check serviceability of a heater of the sensor, having measured resistance between conclusions of HT and B + the socket which has to be 11–16 Ohms. |
| 4. Check presence of tension of the battery between B+ conclusion from the socket from the computer and weight (ignition has to be included). |
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Replacement
| PERFORMANCE ORDER |
| 1. Start the engine for 1–2 min. Disconnect the battery from weight and lift the car. |
| 2. Carefully disconnect the socket from the sensor and turn out the sensor a cap key with a cut. |
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