22 · Diagnostics

Upstream lambda sensor signal error

Make: Alfa Romeo
Model: GT Factory Service Manual
Year: 2003–2010
Section: Examiner › Upstream lambda sensor signal error

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Fault diagnosisUpstream lambda sensor signal error

UPSTREAM LAMBDA SENSOR SIGNAL ERROR

3.2 V6

The diagnostic equipment signals the following error: Upstream lambda signal

1.8 T.SPARK

The diagnostic equipment signals the following error: Upstream lambda signal

3.2 V6

0	PRELIMINARY CHECKS	All OK	Problems encountered	Operation
		Results of the tests
	Connect the diagnostic equipment (Examiner or Examiner Plus) and check the errors and environmental parameters. Check that there is only the upstream Lambda signal error	End of diagnosis	If only the upstream Lambda signal error, Mixture strength, Misfire, Catalyzer and/or Downstream Lambda signal is present	Move on to Step 1
		End of diagnosis	Other errors present	Identify and eliminate the cause of the problem. Move on to Step 8
1	ERROR DETAIL CHECK	All OK	Problems encountered	Operation
	Check the upstream Lambda signal error detail In particular, check that it is not invalid/below minimum level signal	Move on to Step 3	The detail is above the upper limit with error P0133, P0153, P0139, P0159, P1133 and/or P1153	Continue as indicated in See table See table Z57 UPSTREAM LAMBDA SENSOR SIGNAL ERROR
			The detail is below the lower limit	Continue as indicated in See table See table Z57 UPSTREAM LAMBDA SENSOR SIGNAL ERROR
			The detail is invalid/below minimum level signal	Move on to Step 2
2	INTAKE AND EXHAUST SYSTEM SEAL CHECK	All OK	Problems encountered	Operation
	Check the exhaust system by looking and listening. In particular, check that there are no leaks before the upstream Lambda sensor	Move on to Step 3	There are leaks	Restore the correct seal for the exhaust system, if necessary, replace the components involved
3	UPSTREAM LAMBDA SENSOR SWITCHING CHECK	All OK	Problems encountered	Operation
	Using the diagnostic equipment, cancel the errors in the control unit. Start up the engine, let it warm up and, using the diagnostic equipment, check the activation of the 1st loop mixture strength check (or, alternatively the upstream Lambda signal switching)	Move on to Step 4	The activation does not take place (or the signal does not switch)	Move on to Step 6
4	LAMBDA SENSOR WIRING CHECK	All OK	Problems encountered	Operation
	Check the upstream Lambda sensor wiring, checking that there are no false contacts See See E5030 PETROL ENGINE ELECTRONIC MANAGEMENT	Move on to Step 5	There are false contacts	Restore the correct connections. If necessary, replace the defective components. Move on to Step 8
5	ECU SOFTWARE CHECK	All OK	Problems encountered	Operation
	Check, using FIAT documentation, for the existence of updated engine management software calibration	Move on to Step 8	There is no updated software calibration for the control unit	Reprogramme the engine management control unit. Move on to Step 8
6	LAMBDA SENSOR/ECU INPUT WIRING CHECK	All OK	Problems encountered	Operation
	Check the wiring for the ECU upstream Lambda sensor input circuit, checking that there are no short circuits to earth, open circuits or false contacts See See E5030 PETROL ENGINE ELECTRONIC MANAGEMENT	Move on to Step 7	There are faulty connections	Restore the correct connections. If necessary, replace the defective components. Move on to Step 8
7	UPSTREAM LAMBDA SENSOR REPLACEMENT	All OK	Problems encountered	Operation
	Replace the upstream Lambda sensors	Move on to Step 8
8	ERROR CANCELLING AND CHECK	All OK	Problems encountered	Operation
	Using the diagnostic equipment, cancel the errors in the control unit. Road test the vehicle and check that the errror does not occur again	Move on 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
		Move on 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 the Service Department for further information on the problem
9	CHECK ON CORRECT OPERATION	All OK	Problems encountered	Operation
	Check that the fault is no longer present	End of diagnosis

1.8 T.SPARK

0	PRELIMINARY CHECKS	All OK	Problems encountered	Operation
		Results of the tests
	Connect the diagnostic equipment (Examiner or Examiner Plus) and check the errors and environmental parameters. Check that there is only the "upstream Lambda signal" error		If only the upstream Lambda signal error, Mixture strength, Misfire, Catalyzer and/or Downstream Lambda signal is present	Move on to Step 1 1
			Identify and eliminate the cause of the problem.	Move on to Step 8 1
1	CHECK	All OK	Problems encountered	Operation
	Check the upstream Lambda signal error detail In particular, check that it is not invalid/below minimum level signal	Move on to Step 3 1	The detail is above the upper limit with error P0133, P0153, P0139, P1133 and/or P1153	Continue following the instructions in the Table See table Z57 UPSTREAM LAMBDA SENSOR SIGNAL ERROR
			The detail is below the lower limit	Continue following the instructions in the Table See table Z57 UPSTREAM LAMBDA SENSOR SIGNAL ERROR
			The detail is invalid/below minimum level signal	Move on to Step 2 1
2	INTAKE AND EXHAUST SYSTEM SEAL CHECK	All OK	Problems encountered	Operation
	Check the exhaust system by looking and listening. In particular, check that there are no leaks before the upstream Lambda sensor	Move on to Step 3	There are leaks	Restore the correct seal for the exhaust system, if necessary, replace the components involved
3	UPSTREAM LAMBDA SENSOR SWITCHING CHECK	All OK	Problems encountered	Operation
	Cancel the errors in the control unit using the diagnostic equipment. Start up the engine, let it warm up and, using the diagnostic equipment, check the activation of the 1st loop mixture strength check (or, alternatively the upstream Lambda signal switching)	Move on to Step 4	The activation does not take place (or the signal does not switch)	Move on to Step 6
4	LAMBDA SENSOR WIRING CHECK	All OK	Problems encountered	Operation
	Check the upstream Lambda sensor wiring, checking that there are no false contacts: Wiring Diagram See E5030 PETROL ENGINE ELECTRONIC MANAGEMENT	Move on to Step 5	There are false contacts	Restore the correct connections. If necessary, replace the defective components. Move on to Step 8
5	ECU SOFTWARE CHECK	All OK	Problems encountered	Operation
	Check, using the documentation, for the existence of updated engine management software calibration	Move on to Step 8	There is no updated software calibration for the control unit	Reprogramme the engine management control unit. Move on to Step 8
6	LAMBDA SENSOR/ECU INPUT WIRING CHECK	All OK	Problems encountered	Operation
	Check the wiring for the ECU upstream Lambda sensor input circuit, checking that there are no short circuits to earth, open circuits or false contacts Wiring Diagram See E5030 PETROL ENGINE ELECTRONIC MANAGEMENT	Move on to Step 7	There are faulty connections	Restore the correct connections. If necessary, replace the defective components. Move on to Step 8
7	UPSTREAM LAMBDA SENSOR CHECK	All OK	Problems encountered	Operation
	Check that the upstream sensor is working properly by carrying out Test 1080BA See Test 1080 EXHAUST EMISSION CONTROL SYSTEM	Move on to Step 8	Lambda sensor defective	Replace the upstream Lambda sensor Op. 1080B90 LAMBDA PROBE R R
8	ERROR CANCELLING AND CHECK	All OK	Problems encountered	Operation
	Using the diagnostic equipment, cancel the errors in the control unit. Road test the vehicle and check that the errror does not occur again	Move on 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	Move on to Step 0
		Move on 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 the Service Department for further information on the problem
9	CHECK ON CORRECT OPERATION	All OK	Problems encountered	Operation
	Check that the fault is no longer present	End of diagnosis

1.8 T.SPARK, 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	End of diagnosis	The Upstream Lambda signal error is present	Continue according to the instructions in See table See table Z56 UPSTREAM LAMBDA SENSOR SIGNAL ERROR
			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 problem. Continue to Step 3
1	SENSOR CHECK	All OK	Problems met	Operation
	Visually inspect: The installation of the sensors; That the terminals are not corroded; That the wiring between the sensor and the ECU is not faulty	Continue to Step 2	Lambda sensors fitted incorrectly	Fit the Lambda sensors correctly 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 See E5030 PETROL ENGINE ELECTRONIC MANAGEMENT Continue to Step 3
2	REPLACING UPSTREAM LAMBDA SENSORS	All OK	Problems met	Operation
	Replace the upstream Lambda sensors. Search for the cause of the pollution in the sensors. 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. 1040A24 and introduce suitable quality fuel. Continue to Step 3
		Continue to Step 3	Engine oil leaks detected	Continue according to the instructions in See table See table X12 ENGINE OIL LEAKS
3	ERROR CANCELLING AND CHECKING	All OK	Problems met	Operation
	Use a tester to cancel the errors in the control unit. Carry out a road test and ensure the error does not recur.	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 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 Service for further information on the problem
4	CHECK ON CORRECT OPERATION	All OK	Problems met	Operation
	Check that the fault is no longer present	End of diagnosis

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