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Fiat Doblò Factory Service Manual (2000-2010)22 · Fault diagnosis
22 · Diagnostics

High co emissions

Make
Fiat
Model
Doblò Factory Service Manual
Year
2000–2010
Section
Emissions › High co emissions
Fault diagnosisHigh co emissions

HIGH CO EMISSIONS

The percentage of CO and/or HC is higher than the recommended figure.

Results of the tests
0PRELIMINARY CHECKSAll OKProblems metOperation
Check the condition of the air filterContinue to Step 1Filter element dirty or damagedReplace the filter element Op. 1048A14
1CHECK WITH DIAGNOSTIC EQUIPMENTAll OKProblems metOperation

Connect diagnostic equipment (Examiner or other instruments) to the diagnostic socket.

Check that there are no faults in the engine management control unit

Continue to Step 2'Supply system' error detectedSee table Z50 MIXTURE STRENGTH ERROR
'Misfire' error detectedSee table Z53 MISFIRE ERROR
'Catalytic converter' error detectedSee table Z55 CATALYZER ERROR
'Upstream lambda sensor' error detectedSee table Z56 UPSTREAM LAMBDA SENSOR SIGNAL ERROR
'Downstream lambda sensor' error detecteSee table Z58 DOWNSTREAM LAMBDA SENSOR SIGNAL ERROR
Another error detected in the control unitContinue following the instructions for the diagnostic equipment
Lack of dialogue with the control unitRestore the connection between the engine management control unit and the diagnostic connector See E5030 PETROL ENGINE ELECTRONIC MANAGEMENT
2ACTIVE DIAGNOSIS WITH DIAGNOSTIC EQUIPMENTAll OKProblems metOperation

Using the diagnostic equipment (Examiner or other iinstruments) carry out active diagnosis on the:

  • vapour recovery solenoid valve
  • Injectors
Continue to Step 3Connections faultyRestore the connection of the injectors and the solenoid with the control unit See E5030 PETROL ENGINE ELECTRONIC MANAGEMENT
Solenoid valve faultyReplace the solenoid valve Op. 1080E28
Faulty injectorReplace injector Op. 1056B70
3CHECKING LAMBDA SENSORAll OKProblems metOperation
Check that the Lambda sensor is working properlyContinue to Step 4Upper lambda sensor defectiveReplace the upper Lambda sensor Op. 1080B94
Lower lambda sensor defectiveReplace the lower Lambda sensor Op. 1080B95
4CHECKING CATALYTIC CONVERTERAll OKProblems metOperation
Check that the catalytic converter is working properlyContinue to Step 5Catalytic converter defectiveReplace the exhaust manifold Op. 1072C16
5CHECKING AIR CIRCUITAll OKProblems metOperation
Check the condition of the air supply circuitContinue to Step 6Circuit component damagedReplace the component involved
6CHECKING FUEL PRESSUREAll OKProblems metOperation
Check the fuel supply pressure Op. 0510C10Continue to Step 7Pressure not correctReplace the fuel pump Op. 1040A70
7CHECKING CORRECT OPERATIONAll OKProblems metOperation
Check that the fault is no longer presentFault persistsSearch for the fault starting from another symptom'

Parts & tools for this job Staging For 2000 Fiat Doblò

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