Monitoring catalytic converter efficiency, function - GF49.10-P-3033V
ENGINES 272.920 in MODEL 203 up to Model Year 08/Modification Year 07
ENGINES 272.922 in MODEL 211
ENGINES 272.940 in MODEL 203 up to Model Year 08/Modification Year 07
ENGINES 272.941 in MODEL 203 up to Model Year 08/Modification Year 07
ENGINES 272.942 in MODEL 171 up to Model Year 08/Modification Year 07
ENGINES 272.943 in MODEL 211, 219
ENGINES 272.944 in MODEL 211
ENGINES 272.945 in MODEL 251 up to Model Year 08/Modification Year 07
ENGINES 272.946 in MODEL 221 up to Model Year 08/Modification Year 07
ENGINES 272.960 in MODEL 203 up to Model Year 08/Modification Year 07
ENGINES 272.963 in MODEL 171 up to Model Year 08/Modification Year 07
ENGINES 272.964 in MODEL 211, 219
ENGINES 272.965 in MODEL 221 up to Model Year 08/Modification Year 07
ENGINES 272.966 in MODEL 230 up to Model Year 08/Modification Year 07
ENGINES 272.967 in MODEL 164, 251 up to Model Year 08/modification year 07
ENGINES 272.970 in MODEL 203 up to Model Year 08/Modification Year 07
ENGINES 272.972 in MODEL 211
ENGINES 272.975 in MODEL 221 up to Model Year 08/Modification Year 07
ENGINES 273.922 in MODEL 221 up to Model Year 08/Modification Year 07
ENGINES 273.923 in MODEL 164 up to Model Year 08/Modification Year 07
ENGINES 273.924 in MODEL 221 up to Model Year 08/Modification Year 07
ENGINES 273.960 in MODEL 211, 219
ENGINES 273.961 in MODEL 216, 221 up to Model Year 08/modification year 07
ENGINES 273.962 in MODEL 211
ENGINES 273.963 in MODEL 164, 251 up to Model Year 08/modification year 07
ENGINES 273.965 in MODEL 230 up to Model Year 08/Modification Year 07
ENGINES 273.967 in MODEL 209
ENGINES 273.968 in MODEL 221 up to Model Year 08/Modification Year 07
ENGINES 272.940 in MODEL 209
ENGINES 272.960 in MODEL 209
Shows model 171
Each catalytic converter is evaluated on the basis of its ability to store oxygen. The oxygen stored during the lean phase is then reduced totally or partially during the rich phases. Aging reduces the ability of catalytic converters to store oxygen. It also reduces the ability to convert HCs.
By law, HC emissions must not go above certain limits. The task of the catalytic converter monitoring is to evaluate aging through the ability to store oxygen and therefore to convert hydrocarbons.
Active diagnosis depends on direct measurement of the oxygen stored during the transition from rich to lean mixture, when the catalytic converter is at operating temperature and the lambda control is enabled. Several measurements are taken in the lower partial load range.
The wideband-lambda sensor is located upstream of the catalytic converter, and is used to obtain precise measurements of the mixture. Downstream of the catalytic converter is a lambda discrete sensor, which identifies its current condition.
During the first stage, the oxygen stored when the mixture is rich (lambda about 0.95) is reduced until the sensor voltage downstream of the converter is over about 650 mV.
The next stage switches to the lean mixture (lambda about 1.05) and monitors how long it takes until the sensor voltage downstream of the converter is below about 200 mV.
If the length of time measured in this way is below the value set as the borderline characteristic for catalytic converters, then oxygen storage capacity is insufficient and the converter must be replaced.
If a fault is detected, the engine diagnosis indicator lamp or the "CHECK ENGINE" indicator lamp
is lit on the instrument cluster. The stored faults can be read out and erased with the STAR DIAGNOSIS.
| Component description for O2 sensors | O2 sensors upstream of TWC | GF07.04-P-6100V |
| O2 sensors downstream of TWC | GF07.04-P-6100VA | |
| ME-SFI [ME] control unit, component description | GF07.61-P-6000V | |
| Three-way catalytic converter, component description | GF49.10-P-2010V | |
| Component description for the "CHECK ENGINE" indicator lamp | GF54.30-P-5011V | |
| Component description for the engine diagnosis indicator lamp | Except |
GF54.30-P-5010V |