GF07.61-P-3020M ME-SFI Two-Sensor Control, Function

GF07.61-P-3020M ME-SFI Two-Sensor Control, Function

Component Identification:

The two-sensor control has the following tasks:
^ Assure long-term stability of the lambda control
^ Monitoring O2 sensors upstream of TWC
^ Monitoring efficiency of catalytic converters.

Component Identification:

The ME engine control unit determines the lambda mean value from signals from the O2 sensors downstream of TWC. This value is compared with a stored value for optimum exhaust emissions. If the deviation is too large after a number of measurements, a correction variable (time delay ± TV ) is determined for the lambda control.
The correction variable (value for new O2 sensor approx. 0) makes it possible to compensate for aging of the O2 sensor upstream of TWC within certain limits. If the correction variable exceeds the limit value the O2 sensor upstream of the TWC must be replaced.
The correction values are map-controlled and are implemented by the ME control unit by adapting the fuel injection.

In addition, allowance is made for the period of the signal supplied by the sensor upstream of TWC. If no sensor state change takes place, the lambda control is not active and therefore a two-sensor control is not possible either.

In case of error the engine diagnosis indicator lamp lights up or for United States of America the CHECK ENGINE indicator lamp in the instrument cluster and a fault is stored in the fault memory.
The stored faults can be read out and erased with the DAS.