On cars the system of onboard diagnostics OBD-II in a control system of the engine which has a feedback between the gauge of oxygen and the engine management block (PCM) is established. It is reached at the expense of installation of the primary gauge of oxygen or the gauge топливовоздушной mixes before каталитическим neutralizer and the secondary gauge of oxygen behind neutralizer. Depending on the oxygen maintenance in the fulfilled gases the oxygen gauge induces pressure corresponding on size. On the basis of this data the engine management block changes time of opening of atomizers and a fuel parity in топливовоздушной mixes. That there was a full combustion of a gas mixture and in the fulfilled gases there were no harmful substances, on 14,7 weight parts of air 1 part of fuel should have.
Defining structure of the fulfilled gases before and after neutralizer, PCM defines efficiency of neutralizer.
Fig. 7.16. An arrangement of gauges of oxygen on models since 2001: 1 – electric sockets; 2 – the oxygen gauge (the block 2, the gauge 2); 3 – the oxygen gauge (the block 1, the gauge 2)
Primary (in the direction of the fulfilled gases) the oxygen gauge is located in a final collector or in an exhaust pipe, and secondary — for каталитическим
neutralizer (fig. 7.16
Do not mix gauges of oxygen and топливовоздушной a mix. They are similar on appearance, but work differently and have various operational characteristics.
Like the oxygen gauge, the gauge топливовоздушной mixes transforms the information to the target pressure transferred to the block of engine management. The signal size is proportional to the relation of a mix of air/fuel in a stream of the fulfilled gases. The gauge топливовоздушной mixes changes target pressure from 3,3 to 3,0 in depending on an oxygen proportion in a stream of the fulfilled gases. Like the oxygen gauge, the gauge топливовоздушной mixes starts to work normally only after warming up for what on gauges establish heaters.
At service of gauges accept following safety measures:
Gauges of oxygen and топливовоздушной mixes have constantly connected braid with wires and an electric socket which are not separable from the gauge. Damage of a braid with wires either its removal or an electric socket can break working capacity of gauges.
Exclude hit of a dirt, greasing and other substances on gauges.
Do not use solvents for clearing of gauges.
Do not throw and do not strike gauges.
As gauges are established in a final collector or an exhaust pipe, they burn, therefore they are very difficult for removing on the cold engine.
Replacement of gauges of oxygen (O2S) make as follows:
To exclude probability of damage of gauges, start up the engine on 1–2 mines, then switch off it. Removal of gauges is facilitated now, however thus it is necessary to be careful not to burn about a hot final collector and an exhaust pipe.
Switch off ignition and disconnect a wire of "weight" from the storage battery.
If it is necessary to remove the secondary gauge, lift the car on the lift.
Fig. 7.17. An arrangement of the primary gauge of oxygen on the block 2 on models since 2001
It is possible to replace the primary gauge, without lifting the car (fig. 7.17
Disconnect the electric socket located on wires of the gauge of oxygen.
Fig. 7.18. An arrangement of the secondary gauge of oxygen on the block 1 on models since 2001
Turn out the gauge from a final collector or an exhaust pipe (fig. 7.18
). For a gauge reversing use cutting накидной a
Put on a gauge carving антипригарный structure which will facilitate the subsequent отворачивание the gauge. The carving of the new gauge is already covered антипригарным by structure. Screw the gauge and reliably tighten it.
Connect an electric socket of the gauge.
Lower the car.
Gauge installation spend to sequences, return to removal.