9.1.2. Oxygen sensor
Fig. 9.1. Control system of the Fenix 5.1 engine: 2/14 — the system relay of the engine; 3/1 — the ignition switch; 4/1 — the block of system management of the Fenix 5.1 engine; 6/13 — the fuel pump; 7/15 — the heated sensor of oxygen (HO2S); 7/21 — the RPM meter (RPM) of the petrol engine;
7/22 — the sensor of absolute pressure in a collector (MAR sensor); 7/23 — the sensor of temperature of cooling liquid of the engine (EST); 7/24 — the sensor of temperature of entrance air; 7/25 — the sensor of provision of a butterfly valve; 7/26 — the sensor of a detonation (KS); 7/27 — the sensor of position of the camshaft; 8/2 — the regulator of idling (IAC); 8/6, 8/7, 8/8, 8/9 — nozzles; 8/12 — the valve of a purge of the coal filter (SR); 10/51 — a precautionary lamp of temperature of exhaust gases; 11/2 — the block of safety locks in passenger salon; 24/20 — the 22-contact socket of a plait of passenger salon (C), a plait of a compartment of the engine (A) (gray); 24/23 — the 22-contact socket of a plait of passenger salon; 24/27 — the 12-contact socket of a plait of a compartment of the engine
(A) — a plait of the module of engine management (ESM); 24/33 — the 4-contact socket of a plait of the module of engine management (unified social tax) (B) (Q); 31/25 — a ground contact under the dashboard
The oxygen sensor 7/15 (fig. 9.1)
is mounted on a reception pipe of the muffler before converter. It is supplied with system of electric heating and it is used for measurement of content of oxygen in exhaust gases that allows BU to determine the level of the required enrichment or impoverishment of fuel mix.
The plate of the sensor turns on two resistors: one carries out a role of a heating element, an another represents the oxygen sensor on the basis of dioxide of the titan. On one conclusion of a heating element tension moves; the second conclusion is used by BU for regulation of temperature by connection with a certain frequency of a heating element with "weight". Duration of impulses defines extent of heating. BU is programmed so that to maintain sensor plate temperature about 700 °C.
One conclusion of the oxygen sensor is connected to "weight" in BU, on the second tension of 5 Century moves.
Operation of the engine on the grown poor mix leads to increase in content of oxygen in exhaust gases. In these conditions resistance of the sensor is big also high entrance voltage (about 4,8 In) — owing to the increased resistance between an entrance of tension and "weight".
During the operation of the engine on the enriched mix the content of oxygen in exhaust gases is not enough or slightly; at the same time resistance of the sensor is not enough and entrance tension falls approximately up to 0,7 Century.