|  |  | Results of the tests | 
| 0 | PRELIMINARY CHECKS | All OK | Problems met | Operation | 
|---|
|  | Connect
the tester (Examiner or Examiner Plus) and transcribe the errors
and environmental parametersCheck for the 'Upstream Lambda signal' error only | End of diagnosis | Only the 'Upstream Lambda
signal', 'Mixture strength', 'Misfire', 'Catalyzer' and/or 'Downstream Lambda
signal' errors are present | Continue to Step  1 | 
| Only the 'Upstream Lambda signal', 'Mixture strength', 'Misfire',
'Catalyzer' and/or 'Downstream Lambda signal' errors are present | Identify and eliminate the cause of the anomaly.Continue
to Step  8 | 
| 1 | ERROR DETAIL CHECK | All OK | Problems met | Operation | 
|---|
| 1.2 16v | Check the detail of the 'Upstream Lambda signal' errorIn particular, check that it is not 'Below minimum limit' | Continue to Step 3 | The detail is 'Above upper limit'
with error P0133, P0139 and/or P1133 | See table    Z57 | 
| The detail is 'Above upper limit' with error P0133, P0139 and/or
P1133 | See table    Z57 | 
| The detail is 'Above upper limit' with error P0133, P0139 and/or
P1133 | Continue to Step  2 | 
| 1.6 16v | Check the detail of the 'Upstream Lambda signal' errorIn particular, check that it is not 'Open circuit or short circuit
to earth' | Continue to Step 3 | The detail is 'Signal not plausible' | See table    Z57 | 
| The detail is 'Open circuit or short circuit to earth' | Continue to Step  2 | 
| 1.8 16v | Check the detail of the 'Upstream Lambda signal' errorIn particular, check that it is not 'Below minimum level' | Continue to Step 3 | The detail is 'Above maximum limit' with error P0133
and/or P0153 | See table    Z57 | 
| The detail is 'Below minimum level' | Continue to Step  2 | 
| 2.4 20v | Check the detail of the 'Upstream Lambda signal' errorIn 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,
P0159, P1133 and/or P1153 | See table    Z57 | 
| The detail is 'Below 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 | Leaks are present | 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 componentsContinue
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 componentsContinue
to Step  8 | 
| 7 | REPLACING UPSTREAM LAMBDA SENSOR | All OK | Problems met | Operation | 
|---|
|  | Replace
the upstream Lambda sensor  Op.   1080B60 | Continue to Step 8 |  |  | 
| 8 | DELETING AND CHECKING ERROR | 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 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 | 
| 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 | CHECKING  CORRECT OPERATION | All OK | Problems met | Operation | 
|---|
|  | Check
that the fault is no longer present | End of diagnosis |  |  |