S 320 LWB (140.033) L6-3.2L (104.994) (1995)
Engine Control Module: Description and Operation
Mixture Preparation Self-Adaption
The Lambda control system determines fuel injection duration precisely so that the fuel/air ratio is kept constant at Lambda level 1 (equals 14.7 kg air to
1 kg fuel) under all operating conditions.
Should malfunctions occur in the form of:
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Intake air teaks,
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Injector wear or carbon build-up,
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Engine wear,
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Contact resistance in mass air flow sensor,
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Defective diaphragm pressure regulator,
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Defective purge switchover valve,
the engine control module automatically corrects the fuel/air mixture by adjusting the fuel injection duration.
The degree of correction is constantly calculated and permanently stored if the following conditions are satisfied:
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Engine coolant temperature < 52 °C at start.
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Engine coolant temperature between 80 and 100 °C while driving,
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Intake air temperature between 0 and 55 °C.
Air/fuel mixture self-adaptation occurs at idle and under partial load. The maximum degree of correction towards rich or lean is 25%. After fuel injection
system or engine repair work is performed, the engine control module will automatically adapt itself after approx. 10 trips. After eliminating a
malfunction or after trial installation of an engine control module from another vehicle, the self-adaptation feature must be reset (see "Resetting and
Reactivating ECM Memory").