E 55 AMG Sedan (211.076) V8-5.5L SC (113.990) (2003)
Component Identification
The mixture composition is controlled within the narrowest possible limits around lambda= 1 in order to achieve a high conversion of the exhaust gases
(exhaust gas conversion) in the catalytic converters.
The O2 sensors upstream of TWC react to the oxygen share in the exhaust and transmits a corresponding voltage signal to the ME control unit. The ME
control unit in turn alters the mixture composition by regulating the injection quantity in such a way that lambda=1. This process is repeated constantly
(control loop).
The lambda closed-loop control is operational in the following operating conditions (closed-loop control):
^
Coolant temperature >52 °C
^
O2 sensors have reached operating temperature
^
Engine idling or partial-load range
^
Deceleration fuel shutoff not active.
The ME control unit alters the mixture composition with a time delay in order to prevent any risk of jerking.
Example:
Assuming a leaner fuel-air mixture is produced. This has the following consequence, that the O sensor voltage drops and the ME control 2 unit
compensates for this lean drift through a matching enrichment.