C 230 CL (203.740) L4-1.8L SC (271.948) (2003)
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Engine Control Module: Description and Operation
GF07.61-P-4022KE ME-SFI Lambda Control, Function
GF07.61-P-4022KE ME-SFI Lambda Control, Function
- up to model year 08
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 sensor upstream of TWC reacts to the oxygen share in the exhaust and transmits a corresponding voltage signal to the ME control unit.
Consequently, the mixture composition is modified by control of the injection quantity, so that lambda=1 is obtained. This process is repeated constantly
(control loop).
The ME-SFI [ME] control unit alters the mixture composition with a time delay in order to prevent any risk of jerking.
Control of the air/fuel ratio is much faster by using a wideband oxygen sensor (continuous signal of lambda 0.7 to 4.0) as an O2 sensor upstream of
TWC.
The function of the lambda control (closed-loop operation) is dependent upon:
^
Coolant temperature at start (dependent on the particular operating condition)
^
Operating temperature of the O2 sensor upstream of TWC
^
Engine idling or partial-load range
^
Deceleration fuel shutoff not active.
Component Identification
