Siemens LMV52.440B1 - AZL Says O2 Trim Control Automatically Deactivated

TechnicalInstructions  LMVSeries
DocumentNo.LV5‐1000
Section7 Page18 SCCInc.

AZLSays“O2TrimControlAutomaticallyDeactivated”

ManydifferentproblemscancausetheO
2
trimcontroltoautomaticallydeactivate.Whenthis
happens,checkthefaulthistory.ThemostrecentfaultwilllikelybeerrorcodeBF,diagnostic
00.ThisistheerrorcodeforanautomaticdeactivationoftheO
2
trim.Checktheprevious
errorcodeinthefaulthistorytoseewhatactuallycausedtheautomaticdeactivation.The
mostcommonare:

1. ErrorcodeB5,diagnosticcode01.ThismeansthatthecurrentO
2
valuewentbelowtheO
2

alarmcurveformorethan3seconds,whichcausedtheO
2
trimtodeactivate.

a. MakesuretheloadnumbersontheRatioControlCurvematchtheactualfuelflow.
Useafuelflowmeterifpossible.

b. Increasethe%O
2
gapbetweentheO
2
ControlCurveandtheO
2
AlarmCurveatand
aroundthepointwherethefaultoccurred(canbedeterminedbytheloadlistedin
thefaulthistory).

Also,parameterO2ModOffsetcanbeincreasedin0.5%increments.Parameter
LoadCtrlSuspendcanbedecreasedin1%increments.SeeSection3formoreinformation
ontheseparameters.

2. ErrorcodeAB,diagnosticcode15or16.Checktheconfigurationoftheambientandstack
temperaturesensors.Ifthesesensorsareactivatedandarenotwiredinorarenot
functioningcorrectly,theO
2
trimwillautomaticallydeactivateimmediatelyafteritis
reactivated.

3. ErrorcodeAB,diagnosticcode20.CheckthetemperatureoftheQGO20sensorusingthe
followingmenupath:

 Params&Display>O2Module>ProcessData>QGOSensorTemp

Thetemperatureshouldbeatleast1202
o
F.Ifthetemperaturefallsbelowthisvalueduring
prepurgeoranytimeduringoperation,the%O
2
cannotbereadandtheO
2
trimwill
automaticallydeactivate.Ifthisisthecase,theQGO20sensormaybemountedimproperly
orthegasvelocitymaybetoohigh.
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