2751147 - Z57 UPSTREAM LAMBDA SENSOR SIGNAL ERROR

The diagnostic equipment signals the following error: Upstream Lambda signal (slow)
Results of the tests
0PRELIMINARY CHECKSAll OKProblems metOperation
Connect the diagnostic equipment (Examiner or Examiner Plus) and record the errors and environmental parameters.Check for the 'Upstream Lambda signal (slow)' error onlyEnd of diagnosisThe 'Upstream Lambda signal' error is presentSee table   Z56 
Only the 'Upstream Lambda signal (slow)', 'Mixture strength', 'Misfire', 'Catalyzer' and/or 'Downstream Lambda signal' errors are presentContinue to Step 1
Other errors are presentIdentify and eliminate the cause of the problem.Continue to Step 3
1SENSOR CHECKAll OKProblems metOperation

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 2Lambda sensor fitted incorrectlyFit the Lambda sensor correctly Op. 1080B60Continue to Step 3
Terminals corrodedReplace faulty componentsContinue to Step 3
Wiring faultyRestore correct connections. If necessary, replace the faulty components See E5030 PETROL ENGINE ELECTRONIC MANAGEMENT Continue to Step 3
2REPLACING UPSTREAM LAMBDA SENSORAll OKProblems metOperation
Replace the upstream Lambda sensor Op. 1080B60Search 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 3Use of contaminated petrolClean the tank Op. 1040A24and introduce suitable quality fuel.Continue to Step 3
Engine oil leaks detectedSearch for the causes of the leak and eliminate it
3ERROR CANCELLING AND CHECKINGAll OKProblems metOperation
Use a tester to cancel the errors in the control unit.Road test the vehicle and check that the error does not occur againContinue to Step 4The 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
The fault persists, but it is the second time that this step has been reached or the Lambda sensor has already been replacedContact Technical Support for further information on the problem
4CHECK ON CORRECT OPERATIONAll OKProblems metOperation
Check that the fault is no longer presentEnd of diagnosis