TechnicalInstructions LMVSeries
DocumentNo.LV5‐1000
Section7 Page18 SCCInc.
AZLSays“O2TrimControlAutomaticallyDeactivated”
ManydifferentproblemscancausetheO
2
trimcontroltoautomaticallydeactivate.Whenthis
happens,checkthefaulthistory.ThemostrecentfaultwilllikelybeerrorcodeBF,diagnostic
00.ThisistheerrorcodeforanautomaticdeactivationoftheO
2
trim.Checktheprevious
errorcodeinthefaulthistorytoseewhatactuallycausedtheautomaticdeactivation.The
mostcommonare:
1. ErrorcodeB5,diagnosticcode01.ThismeansthatthecurrentO
2
valuewentbelowtheO
2
alarmcurveformorethan3seconds,whichcausedtheO
2
trimtodeactivate.
a. MakesuretheloadnumbersontheRatioControlCurvematchtheactualfuelflow.
Useafuelflowmeterifpossible.
b. Increasethe%O
2
gapbetweentheO
2
ControlCurveandtheO
2
AlarmCurveatand
aroundthepointwherethefaultoccurred(canbedeterminedbytheloadlistedin
thefaulthistory).
Also,parameterO2ModOffsetcanbeincreasedin0.5%increments.Parameter
LoadCtrlSuspendcanbedecreasedin1%increments.SeeSection3formoreinformation
ontheseparameters.
2. ErrorcodeAB,diagnosticcode15or16.Checktheconfigurationoftheambientandstack
temperaturesensors.Ifthesesensorsareactivatedandarenotwiredinorarenot
functioningcorrectly,theO
2
trimwillautomaticallydeactivateimmediatelyafteritis
reactivated.
3. ErrorcodeAB,diagnosticcode20.CheckthetemperatureoftheQGO20sensorusingthe
followingmenupath:
Params&Display>O2Module>ProcessData>QGOSensorTemp
Thetemperatureshouldbeatleast1202
o
F.Ifthetemperaturefallsbelowthisvalueduring
prepurgeoranytimeduringoperation,the%O
2
cannotbereadandtheO
2
trimwill
automaticallydeactivate.Ifthisisthecase,theQGO20sensormaybemountedimproperly
orthegasvelocitymaybetoohigh.