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M54engMS43/ST036/6/20000
EMISSIONS RELEVANT:
During an interval of 1000 crankshaft revolutions
the misfire events of all cylinders are
added and if the sum is greater than a predetermined value a fault will be set identifying the
particular cylinder(s). The “Service Engine Soon” light will be illuminated during and after
the second cycle if the fault is again present.
CATALYST DAMAGING:
During an interval of 200 crankshaft revolutions
the misfire events of all cylinders are added
and if the sum is greater than a predetermined value a fault will be set identifying the par-
ticular cylinders(s). The “Service Engine Soon” lamp:
• On vehicles with a Siemens Control Module (M54 engines) - the lamp will immediately go
to a steady illumination since fuel to the injector(s) is removed. Fuel cut-off to the cylin-
der will resume after several (
>>7) periods of decel if crankshaft sensor adaptation is suc-
cessfully completed or the engine is shut-off and restarted.
In each case the number of misfire events permitted is dependent on engine speed, load
and temperature map.
The process of misfire detection continues well after the diagnostic drive cycle requirements
have been completed. Misfire detection is an on-going monitoring process
that is only dis-
continued under certain conditions.
Misfire detection is only disabled under the following conditions:
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REQUIREMENTSSTATUS/CONDITION
Engine Speed< 512 RPM
Engine LoadVarying/Unstable
Throttle AngleVarying/Unstable
TimingTiming retard request active (i.e. knock
control - ASC, AGS)
Engine Start-upUp to 5 seconds after start-up
A/CUp to 0.5 seconds after A/C activation
Decel fuel cut-offActive
Rough road recognitionActive
ASC ControlActive
