Particle filter (F9Q engine): 1 - particulate filter pressure sensor located in the engine compartment); 2 - bellows; 3 - particulate filter: 4 - temperature sensor before the particulate filter: 5 - temperature sensor after the particulate filter: 6 - pressure intake tube before the particulate filter; 7 - pressure intake tube after the anti-particulate filter; 8 - silent block
Particle filter (G9T engine, first version)
Particle filter (G9T engine, second version): 1 - particulate filter pressure sensor located in the engine compartment); 2 - bellows: 3 - particulate filter; 4 - temperature sensor in front of the particulate filter; 5 - temperature sensor after the anti-particulate filter; 6 - pressure intake tube in front of the particulate filter; 7 - pressure intake tube after the anti-particulate filter; 8 - silent block
Safety regulations
Since the exhaust tract is heated to high temperatures, certain precautions must be observed. In particular, it is forbidden to open and disconnect the pressure measuring circuit, except for its connection to the exhaust system (the tightness of the pressure measuring circuit can only be ensured by the manufacturer).
In addition, incorrect installation of the pressure measuring tubes causes their flexible parts to twist: This creates low points in them, in which water contained in the exhaust gases accumulates, which at low temperatures will freeze and cause the tubes to burst.
Note. Do not stop the car with the engine running in places where there are combustible materials (dry grass, fallen leaves), which can ignite on contact with a hot exhaust system.
Principle of operation
The underbody particulate filter, located at the outlet of the pre-catalytic converter, serves to reduce emissions of toxic substances by trapping solid particles of unburned fuel contained in the exhaust gases (at the stage of filter loading or filtration), after which the afterburning of these particles occurs (during filter regeneration).
Based on the information from the sensors, the injection computer determines the temperature and pressure of the exhaust gases at the inlet, then at the outlet of the diesel particulate filter.
The injection ECU constantly determines the degree of contamination of the particle filter based on the difference in pressure between its inlet and outlet. When the filter is sufficiently loaded with particles, the ECU determines from the inlet and outlet temperatures whether the temperature is high enough (approximately 600 'C), to start filter regeneration.
Regeneration is carried out by afterburning the solid particles trapped by the filter: for this, the injection system is switched to the injection delay mode», causing unburned fuel in the combustion chambers of the cylinders to enter the cells of the diesel particulate filter and cause ignition of particulate deposits.
The degree of contamination of the particle filter depends on the driving style of the driver:
- in medium driving (driving in a mixed and extra-urban cycle lasting more than 15 minutes) particulate filter automatically burns off particulate matter without the driver noticing (except for the possible emission of light smoke): this is a stage «spontaneous regeneration»;
- if the operating temperature in the exhaust system does not provide conditions for spontaneous regeneration, the degree of filter contamination increases, and when it reaches a value of 35 g, the driver is asked to increase the speed by turning on the signal lamp in the instrument panel to ensure spontaneous filter regeneration. The same thing happens with several unsuccessful regeneration attempts;
- if these conditions are still not met and the accumulated soot mass exceeds 45 g. In this case, it is necessary to perform a -static regeneration using a diagnostic tool in a workshop environment.