22 · Diagnostics

Upstream lambda sensor signal error

Make: Alfa Romeo
Model: 147 Factory Service Manual
Year: 2000–2004
Section: Examiner › Upstream lambda sensor signal error

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Fault diagnosisUpstream lambda sensor signal error

UPSTREAM LAMBDA SENSOR SIGNAL ERROR

1.6 TS, 2.0 TS

The diagnostic equipment signals the following error: Upstream Lambda signal

0	PRELIMINARY CHECKS	All OK	Problems met	Operation
		Results of the tests
	Connect the diagnostic equipment (Examiner or Examiner Plus) and record the errors and environmental parameters. Check for the 'Upstream Lambda signal' error only		Only the 'Upstream Lambda signal', 'Mixture strength', 'Misfire', 'Catalyzer' and/or 'Downstream Lambda signal' errors are present	Continue to Step 1
			Identify and eliminate the cause of the anomaly.	Continue to Step 8
1	CHECK	All OK	Problems met	Operation
	Check the detail of the 'Upstream Lambda signal' error In particular check that it is not 'Signal not valid/Below minimum threshold'	Continue to Step 3	The detail is 'Above upper limit' with error P0133, P0153, P0139, P1133 and/or P1153	See table Z57
			The detail is 'Below the lower limit'	See table Z57
			The detail is 'Signal not valid/Below minimum threshold'	Continue to Step 2
2	INTAKE AND EXHAUST SYSTEM LEAKAGE CHECK	All OK	Problems met	Operation
	Check the exhaust system visually and by listening. In particular, check that there are no leaks before the upstream Lambda sensor	Continue to Step 3	There are leaks	Eliminate the leaks from the exhaust system, if necessary, replace the components involved
3	UPSTREAM LAMBDA SENSOR SWITCHING CHECK	All OK	Problems met	Operation
	Use a tester to cancel the errors in the control unit. Start the engine, let it warm up and check the activation of the 1st loop mixture strength check using the diagnostic equipment (or, alternatively, the switching of the upstream Lambda signal)	Continue to Step 4	The activation does not take place (or the signal does not switch)	Continue to Step 6
4	LAMBDA SENSOR WIRING CHECK	All OK	Problems met	Operation
	Check the upstream Lambda sensor wiring, checking that there are no false contacts See E5030 PETROL ENGINE ELECTRONIC MANAGEMENT	Continue to Step 5	There are false contacts	Restore correct connections. If necessary, replace the defective components Continue to Step 8
5	ECU SOFTWARE CHECK	All OK	Problems met	Operation
	Using the FIAT documentation, check that the engine management software calibration is updated	Continue to Step 8	The control unit does not have updated software setting	Reprogramme the engine management control unit. Continue to Step 8
6	LAMBDA SENSOR/ECU INPUT WIRING CHECK	All OK	Problems met	Operation
	Check the wiring for the upstream Lambda sensor intake circuit in the ECU, checking that there are no short circuits to the supply or to earth, open circuits or false contacts See E5030 PETROL ENGINE ELECTRONIC MANAGEMENT	Continue to Step 7	There are faulty connections	Restore correct connections. If necessary, replace the defective components Continue to Step 8
7	REPLACING UPSTREAM LAMBDA SENSOR	All OK	Problems met	Operation
	Replace the upstream Lambda sensor Op. 1080B90	Continue to Step 8
8	ERROR CANCELLING AND CHECKING	All OK	Problems met	Operation
	Use a tester to cancel the errors in the control unit. Road test the vehicle and check that the error does not occur again	Continue to Step 9	The fault persists, it is the first time that this step has been reached and the Lambda sensor has not yet been replaced	Continue to Step 0
		Continue to Step 9	The fault persists, but it is the second time that this step has been reached, or the Lambda sensor has already been replaced	Contact Technical Support for further information on the problem
9	CORRECT OPERATION CHECK	All OK	Problems met	Operation
	Check that the fault is no longer present		Fault persists	Search for the fault starting from another symptom'

3.2 V6

The diagnostic equipment signals the following error: Upstream Lambda signal

0	PRELIMINARY CHECKS	All OK	Problems met	Operation
		Results of the tests
	Connect the diagnostic equipment (Examiner or Examiner Plus) and record the errors and environmental parameters. Check for the 'Upstream Lambda signal' error only		Only the 'Upstream Lambda signal', 'Mixture strength', 'Misfire', 'Catalyzer' and/or 'Downstream Lambda signal' errors are present	Continue to Step 1
			Identify and eliminate the cause of the anomaly.	Continue to Step 8
1	ERROR DETAIL CHECK	All OK	Problems met	Operation
	Check the detail of the 'Upstream Lambda signal' error In particular check that it is not 'Signal not valid/Below minimum threshold'	Continue to Step 3	The detail is 'Above upper limit' with error P0133, P0153, P0139, P1133 and/or P1153	See table Z57
			The detail is 'Below the lower limit'	See table Z57
			The detail is 'Signal not valid/Below minimum threshold'	Continue to Step 2
2	INTAKE AND EXHAUST SYSTEM LEAKAGE CHECK	All OK	Problems met	Operation
	Check the exhaust system visually and by listening. In particular, check that there are no leaks before the upstream Lambda sensor	Continue to Step 3	There are leaks	Eliminate the leaks from the exhaust system, if necessary, replace the components involved
3	UPSTREAM LAMBDA SENSOR SWITCHING CHECK	All OK	Problems met	Operation
	Use a tester to cancel the errors in the control unit. Start the engine, let it warm up and check the activation of the 1st loop mixture strength check using the diagnostic equipment (or, alternatively, the switching of the upstream Lambda signal)	Continue to Step 4	The activation does not take place (or the signal does not switch)	Continue to Step 6
4	LAMBDA SENSOR WIRING CHECK	All OK	Problems met	Operation
	Check the upstream Lambda sensor wiring, checking that there are no false contacts See E5030 PETROL ENGINE ELECTRONIC MANAGEMENT	Continue to Step 5	There are false contacts	Restore correct connections. If necessary, replace the defective components Continue to Step 8
5	ECU SOFTWARE CHECK	All OK	Problems met	Operation
	Using the FIAT documentation, check that the engine management software calibration is updated	Continue to Step 8	The control unit does not have updated software setting	Reprogramme the engine management control unit. Continue to Step 8
6	LAMBDA SENSOR/ECU INPUT WIRING CHECK	All OK	Problems met	Operation
	Check the wiring for the upstream Lambda sensor intake circuit in the ECU, checking that there are no short circuits to the supply or to earth, open circuits or false contacts See E5030 PETROL ENGINE ELECTRONIC MANAGEMENT	Continue to Step 7	There are faulty connections	Restore correct connections. If necessary, replace the defective components Continue to Step 8
7	REPLACING UPSTREAM LAMBDA SENSOR	All OK	Problems met	Operation
	Replace the upstream Lambda sensor Op. 1080B90	Continue to Step 8
8	ERROR CANCELLING AND CHECKING	All OK	Problems met	Operation
	Use a tester to cancel the errors in the control unit. Road test the vehicle and check that the error does not occur again	Continue to Step 9	The fault persists, it is the first time that this step has been reached and the Lambda sensor has not yet been replaced	Continue to Step 0
		Continue to Step 9	The fault persists, but it is the second time that this step has been reached, or the Lambda sensor has already been replaced	Contact Technical Support for further information on the problem
9	CORRECT OPERATION CHECK	All OK	Problems met	Operation
	Check that the fault is no longer present	End of diagnosis	Fault persists

1.6 TS, 2.0 TS

The diagnostic equipment signals the following error: Upstream Lambda signal (slow)

0	PRELIMINARY CHECKS	All OK	Problems met	Operation
		Results of the tests
	Connect the diagnostic equipment (Examiner or Examiner Plus) and record the errors and environmental parameters. Check for the 'Upstream Lambda signal (slow)' error only		The 'Upstream Lambda signal' error is present	See table Z56
			Only the 'Upstream Lambda signal (slow)', 'Mixture strength', 'Misfire', 'Catalyzer' and/or 'Downstream Lambda signal' errors are present	Continue to Step 1
			Other errors are present	Identify and eliminate the cause of the anomaly. Continue to Step 3
1	SENSOR CHECK	All OK	Problems met	Operation
	Visually inspect: the fitting of the sensor; that the terminals are not corroded; that the wiring between the sensor and the ECU is not faulty.	Continue to Step 2	Lambda sensor fitted incorrectly	Fit the Lambda sensor correctly Op. 1080B90 Continue to Step 3
			Terminals corroded	Replace faulty components Continue to Step 3
			Wiring faulty	Restore correct connections. If necessary, replace the faulty components See E5030 PETROL ENGINE ELECTRONIC MANAGEMENT Continue to Step 3
2	REPLACING UPSTREAM LAMBDA SENSOR	All OK	Problems met	Operation
	Replace the upstream Lambda sensor Op. 1080B90 Search for the cause of the pollution in the sensor. The probable causes are: contaminated petrol; engine oil leaks; improper use of fastenings at sensor connector.	Continue to Step 3	Use of contaminated petrol	Clean the tank Op. 1040A24and introduce suitable quality fuel. Continue to Step 3
		Continue to Step 3	Engine oil leaks detected	See table X12
3	ERROR CANCELLING AND CHECKING	All OK	Problems met	Operation
	Use a tester to cancel the errors in the control unit. Road test the vehicle and check that the error does not occur again	Continue to Step 4	The fault persists, it is the first time that this step has been reached and the Lambda sensor has not yet been replaced	Continue to Step 0
		Continue to Step 4	The fault persists, but it is the second time that this step has been reached or the Lambda sensor has already been replaced	Contact Technical Support for further information on the problem
4	CORRECT OPERATION CHECK	All OK	Problems met	Operation
	Check that the fault is no longer present		Fault persists	Search for the fault starting from another symptom'

3.2 V6

The diagnostic equipment signals the following error: Upstream Lambda signal (slow)

0	PRELIMINARY CHECKS	All OK	Problems met	Operation
		Results of the tests
	Connect the diagnostic equipment (Examiner or Examiner Plus) and record the errors and environmental parameters. Check for the 'Upstream Lambda signal (slow)' error only		The 'Upstream Lambda signal' error is present	See table Z56
			Only the 'Upstream Lambda signal (slow)', 'Mixture strength', 'Misfire', 'Catalyzer' and/or 'Downstream Lambda signal' errors are present	Continue to Step 1
			Other errors are present	Identify and eliminate the cause of the anomaly. Continue to Step 3
1	SENSOR CHECK	All OK	Problems met	Operation
	Visually inspect: the fitting of the sensor; that the terminals are not corroded; that the wiring between the sensor and the ECU is not faulty.	Continue to Step 2	Lambda sensor fitted incorrectly	Fit the Lambda sensor correctly Op. 1080B60 Continue to Step 3
			Terminals corroded	Replace faulty components Continue to Step 3
			Wiring faulty	Restore correct connections. If necessary, replace the faulty components See E5030 PETROL ENGINE ELECTRONIC MANAGEMENT Continue to Step 3
2	REPLACING UPSTREAM LAMBDA SENSOR	All OK	Problems met	Operation
	Replace the upstream Lambda sensor Op. 1080B90 Search for the cause of the pollution in the sensor. The probable causes are: contaminated petrol; engine oil leaks; improper use of fastenings at sensor connector.	Continue to Step 3	Use of contaminated petrol	Clean the tank Op. 1040A24and introduce suitable quality fuel. Continue to Step 3
		Continue to Step 3	Engine oil leaks detected	See table X12
3	ERROR CANCELLING AND CHECKING	All OK	Problems met	Operation
	Use a tester to cancel the errors in the control unit. Road test the vehicle and check that the error does not occur again	Continue to Step 4	The fault persists, it is the first time that this step has been reached and the Lambda sensor has not yet been replaced	Continue to Step 0
		Continue to Step 4	The fault persists, but it is the second time that this step has been reached or the Lambda sensor has already been replaced	Contact Technical Support for further information on the problem
4	CORRECT OPERATION CHECK	All OK	Problems met	Operation
	Check that the fault is no longer present		Fault persists	Search for the fault starting from another symptom'

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