18 · Diagnostics

W01 High co emission

Make: Alfa Romeo
Model: 147 Factory Service Manual
Year: 2000–2002
Section: Emissions › W01 High co emission

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Fault diagnosisW01 High co emission

W01 High co emission

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

Step	Test procedure	Result	Action
0	PRELIMINARY CHECKS Check the condition of the air filter	OK	Move onto step 1
0		Filter element dirty or damaged	Replace the filter element Op. 1048A14 End of diagnosis
1	CHECK WITH DIAGNOSTIC EQUIPMENT Connect diagnostic equipment (Examiner or other instruments) to the diagnostic socket. Check that there are no faults in the engine management control unit	OK	Move onto step 2
		'Fuel system' error appears	See table Z50 MIXTURE STRENGTH ERROR End of diagnosis
		'Misfiring' error appears	See table Z53 MISFIRE ERROR End of diagnosis
		'Catalytic converter' error appears	See table Z55 CATALYZER ERROR End of diagnosis
		'Upstream lambda probe' error appears	See table Z56 UPSTREAM LAMBDA SENSOR SIGNAL ERROR End of diagnosis
		'Downstream lambda probe' error appears	See table Z58 DOWNSTREAM LAMBDA SENSOR SIGNAL ERROR End of diagnosis
		Another error detected in the control unit	Continue following the instructions for the diagnostic equipment End of diagnosis
		Lack of dialogue with the control unit	Restore the connection between the engine management control unit and the diagnostic connector Wiring diagram E5030 PETROL ENGINES ELECTRONIC CONTROL End of diagnosis
2	ACTIVE DIAGNOSIS WITH DIAGNOSTIC EQUIPMENT Using the diagnostic equipment (Examiner or other iinstruments) carry out the active diagnosis: vapour recovery solenoid valve Injectors	OK	Move onto step 3
		Connections faulty	Restore the connection between the injectors and the solenoid and the control unit Wiring diagram E5030 PETROL ENGINES ELECTRONIC CONTROL End of diagnosis
		Solenoid valve faulty	Replace the solenoid valve Op. 1080E28 End of diagnosis
		injector anomaly	Replace the injector Op. 1056B70 End of diagnosis
3	CHECKING LAMBDA SENSOR Check that the Lambda sensor is working properly	OK	Move onto step 4
3		Lambda sensor defective	Replace the Lambda sensor Op. 1080B60 End of diagnosis
4	CHECKING CATALYTIC CONVERTER Check that the catalytic converter is working properly	OK	Move onto step 5
4		Catalytic converter defective	Replace the exhaust manifold Op. 1072C12 End of diagnosis
5	CHECKING AIR CIRCUIT Check the condition of the air intake circuit	OK	Move onto step 6
5		Circuit component damaged	Replace the component involved End of diagnosis
6	CHECKING FUEL PRESSURE Check the fuel supply pressure Op. 0510C10	OK	Move onto step 7
6		Pressure not correct	Replace the fuel pump Op. 1040A70 End of diagnosis
7	CHECKING CORRECT OPERATION Check that the fault is no longer present	OK	Incorrect selection of diagnostic procedure
7		Fault persists	Incorrect selection of diagnostic procedure

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Parts & tools for this job For 2000 Alfa Romeo 147

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