Example illustration M254 |
1 | Oxygen sensor 1 |
2 | Oxygen sensor 2 |
3 | Lambda sensor 3 |
4 | Temperature sensor downstream of TWC |
5 | Temperature sensor upstream of the CAT |
P07.04-A105-76
1 | Oxygen sensor 1 |
5 | Temperature sensor upstream of the CAT |
6 | Differential pressure sensor downstream of soot particulate filter |
7 | Differential pressure sensor upstream of soot particulate filter |
P07.04-A106-76
Overview
This document contains information on:
General
Function
General
The 3rd lambda sensor downstream of the gasoline particulate filter is available in engines with a coated gasoline particulate filter (COPF). It is necessary to monitor the catalytic coating of the gasoline particulate filter and regenerate the gasoline particulate filter.
Function
Exhaust gas cleaning in the gasoline particulate filter with third lambda sensor
The gasoline particulate filter captures the emitted soot particles.
The exhaust gas temperature is detected by the temperature sensor upstream of the gasoline particulate filter. The soot content is determined by the gasoline particulate filter differential pressure sensor.
The combustion engine control unit reads the sensor signals in directly and evaluates them. If the measured values exceed specific limits, the combustion engine control unit initiates corresponding interventions in the engine timing, which cause the temperature in the soot particulate filter to increase.
Via a third lambda sensor, the engine is operated so that oxygen for the oxidation of the collected particles is supplied in a targeted manner to the coated soot particulate filter.
Regeneration of gasoline particulate filter
The regeneration (soot combustion) of the gasoline particulate filter takes place while the vehicle is being operated in conventional driving style, predominantly in overrun mode. The soot is burned off as soon as there is a sufficient supply of oxygen available in the gasoline particulate filter and a temperature of 550 °C is exceeded.