Catalytic converter efficiency monitoring function - GF49.10-P-3033BK
ENGINE 113.967 in MODEL 219
ENGINE 113.964 in MODEL 164.1
ENGINE 113.971 in MODEL 251
Shows model 219
Each firewall catalytic converter is evaluated on its ability to store oxygen. A property of catalytic converters is that they are able 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 ageing through the ability to store oxygen and therefore to convert hydrocarbons.
When the catalytic converters are at operating state temperature and the lambda control has been enabled, the O2 sensor signals downstream TWC are compared with the O2 sensor signals upstream TWC. The amplitude of the O2 sensor voltage downstream TWC must be less than the amplitude of the O2 sensor voltage upstream TWC (Note: for example if no monolith was built into the catalytic converter, the O2 sensor signals upstream or downstream TWC would be identical).
Several measurements must be performed in the specified engine speed and load range. The results are compared with a performance map by the motor electronics control unit and the faults detected are stored in the diagnostic trouble code memory.
If a fault is detected, the engine diagnosis indicator lamp or the "CHECK ENGINE" MIL
is lit on the instrument cluster. The stored faults can be read out and erased with the STAR DIAGNOSIS.
| O2 sensor, component description | GF07.04-P-6100BK | |
| Motor electronics control unit, component description | GF07.61-P-6000BK | |
| Three-way catalytic convertor - component description | GF49.10-P-2010BK | |
| Engine diagnosis indicator lamp - component description Except | GF54.30-P-5010BK | |
| "CHECK ENGINE" MIL - component description | GF54.30-P-5011BK |