Exhaust Gas Cleaning, Basic Function - GF49.00-P-1000A
Engine All (4xWD)
Engine All (CAR)
Overview
This document contains information on:
- General
- Function requirements
- Function
General
Exhaust gas cleaning fulfills a central task of the exhaust gas aftertreatment. Exhaust gas cleaning ensures the targeted reduction of exhaust gas emissions.
Function requirements
- Engine management ON (circuit 87M)
- Engine in operation
- Catalytic converters at operating temperature (approx. 300°C)
- Stoichiometric fuel/air ratio in the exhaust gas
- Coolant temperature and exhaust gas temperature reached for gasoline particulate filter regeneration phase
Function
The following exhaust gases that are hazardous to health and the environment are generated during fuel combustion, for example:
- Nitrogen oxides (NOx )
- Hydrocarbon (HC)
- Carbon monoxide (CO)
Catalytic converters are used for exhaust gas cleaning. The requirement for efficient exhaust gas cleaning is a defined mixture formation, which ensures a stoichiometric fuel/air ratio in the exhaust gas for cleaning. The optimum effect of the catalytic converter is ensured in this area.
A mixing ratio of 14.7 kg of air to 1 kg of fuel is necessary in order to achieve theoretically complete combustion. The ratio of air to fuel is a "stoichiometric ratio" (lambda λ). If the air volume delivered corresponds to the theoretical air requirement, this results in the value λ = 1.
In diesel engines in particular, but also in spark-ignition engines, there are also exhaust gas emissions in the form of soot particles. A gasoline particulate filter is used for cleaning here.
The following catalytic converters and gasoline particulate filters are used for exhaust gas cleaning:
| Diesel engine | Spark-ignition engine |
|---|---|
| Oxidation catalytic converter: Vehicle catalytic converter for converting the pollutants carbon monoxide and hydrocarbons that arise during fuel combustion into carbon dioxide (CO2 ) and water (H2 O). As it is an upstream component, it also contributes to removing NOx from the exhaust gases. For this purpose, it converts nitric oxide (NO) into nitrogen dioxide (NO2 ) | Three-way catalytic converter: Vehicle catalytic converter with lambda control for exhaust gas aftertreatment in vehicles with a spark-ignition engine. Carbon monoxide, nitrogen oxide and unburned hydrocarbons are converted into carbon dioxide (CO2 ), nitrogen (N2 ) and water (H2 O). |
| SCR catalytic converter: Vehicle catalytic converter for the reduction of nitrogen oxide emissions using ammonia (NH3 ). Ammonia is generated with the aid of a reduction agent. The nitrogen oxide in the exhaust gas reacts with ammonia and oxygen to form molecular nitrogen (N2 ) and water vapor. | Gasoline particulate filter: Filter unit that filters and stores soot particles that are generated during the combustion process. It also ensures soot particle oxidization during gasoline particulate filter regeneration. |
| Gasoline particulate filter: Filter unit that filters and stores soot particles that are generated during the combustion process. It also ensures soot particle combustion during the regeneration of the gasoline particulate filter. |
Depending on the fuel type, injection procedure, combustion temperature and pressure, different concentrations of nitrogen oxide are generated in the exhaust gas during the combustion of the fuel/air mixture. Different types or combinations of catalytic converters are used in order to ensure compliance with the emissions limit value required by law.
| Function schematics | |||
| Function schematic for exhaust gas cleaning | Engine 608 in model 118, 177, 247 Engine 654 in model 213, 238, 257 | PE49.00-P-2500-97A | |
| Engine 654 in model 118, 167, 177, 247 Engine 656 in model 167 | PE49.00-P-2500-97B | ||
| Engine 176, 177 in model 167 Engine 177.8 in model 290 | PE49.00-P-2500-97C | ||
| Engine 139, 282 in model 118, 177, 247 | PE49.00-P-2500-97D | ||
| Engine 177.8 in model 192, 223, 232 | PE49.00-P-2500-97E | ||
| Engine 254 in model 167 as of model year 2023 Engine 254 in model 206, 214, 236, 254 Engine 256 in model 214, 223, 236 | PE49.00-P-2500-97F | ||
| Engine 139 in model 192, 206, 232, 236, 254 | PE49.00-P-2500-97G | ||
| Engine 654 in model 206, 214, 236, 254 Engine 656 in model 223 | PE49.00-P-2500-97H | ||
| Engine 279 in model 223 | PE49.00-P-2500-97I | ||
| Engine 176 in model 223 | PE49.00-P-2500-97J | ||
| Engine 274 in model 213 as of model year 2021 | PE49.00-P-2500-97K | ||
| Engine 656 in model 464 | PE49.00-P-2500-97L | ||
| Engine 260 in model 118, 177, 247 | PE49.00-P-2500-97M | ||
| Additional basic functions | |||
| Catalytic process, basic function | GF49.20-P-1004A | ||
| Soot particulate filter, basic function | Engine 608 in model 118, 177, 247 with code 460 (Canada version) with code 494 (US version) Engine 654 in model 118, 177, 206, 247, 254 with code 460 (Canada version) with code 494 (US version) Engine 654 in model 213, 238, 257 as of model year 2021 with code 460 (Canada version) with code 494 (US version) Engine 656 in model 167, 223 with code 460 (Canada version) with code 494 (US version) Engine 656 in model 213, 238, 257 as of model year 2021 with code 460 (Canada version) with code 494 (US version) |
GF49.20-P-1007A | |
| Soot particulate sensor control unit, basic function | Engine 608 in model 118, 177, 247 with code 460 (Canada version) with code 494 (US version) Engine 654 in model 118, 167, 177, 206, 214, 247, 254 with code 460 (Canada version) with code 494 (US version) Engine 654 in model 213, 238, 257 as of model year 2021 with code 460 (Canada version) with code 494 (US version) Engine 656 in model 167, 223 with code 460 (Canada version) with code 494 (US version) Engine 656 in model 213, 238, 257 as of model year 2021 with code 460 (Canada version) with code 494 (US version) |
GF49.20-P-9893A |