2427638 - Z52 LEAN FUEL SYSTEM
The Customer reports occasional hardening during the rotation of the steering wheel (no power assistance), without the failure warning light coming on| Results of the tests | ||||
| 1 | INTAKE AND EXHAUST SYSTEM LEAKAGE CHECK | All OK | Problems met | Operation |
|---|---|---|---|---|
| Check
the intake and exhaust system visually and by listening, to check
that there are no leaks downstream of the MAP sensor/flow meter. Also take into account:
| Continue to Step 2 | There are leaks | Eliminate leaks from the system. Replace faulty parts if necessary Continue to Step 5 | |
| 2 | PETROL PRESSURE CHECK | All OK | Problems met | Operation |
| Turn the key to MAR and check that fuel pump activates.Whilst the pump is activated, check that the fuel pressure is not too low | Continue to Step 3 | Low pressure: fuel filter blocked/obstructed | Replace the fuel pump Op. 1040A70 Continue to Step 5 | |
| Low pressure: supply pipe restrictions/leaks | Renew or, if necessary, replace the pipes involved | |||
| Low pressure: pressure regulator defective | Replace the fuel pupm Op. 1040A70 Continue to Step 5 | |||
| Low pressure: pressure regulator incorrectly calibrated | Replace the fuel pump Op. 1040A70 Continue to Step 5 | |||
| Low pressure: electrical problem in the fuel pump | Low pressure: electrical problem in the fuel pump See E5030 PETROL ENGINE ELECTRONIC MANAGEMENT If necessary, replace the fuel pump Op. 1040A70 Continue to Step 5 | |||
| Low pressure: excess pressure valve stuck open | Replace the fuel pupm Op. 1040A70 Continue to Step 5 | |||
| 3 | FUEL QUALITY CHECK | All OK | Problems met | Operation |
| Check that there is no water or other substances in the tank which is contaminating the fuel. | Continue to Step 4 | Impurities present | Clean the tank Op. 1040A24and introduce new fuel.Continue to Step 5 | |
| 4 | UPSTREAM LAMBDA SENSOR CHECK | All OK | Problems met | Operation |
| Continue as instructed in the Table See table Z56 UPSTREAM LAMBDA SENSOR SIGNAL ERROR , starting from Step 3 | End of diagnosis | |||
| 5 | 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 6 | The fault persists | Continue to Step 1 | |
| 6 | CHECK ON CORRECT OPERATION | All OK | Problems met | Operation |
| Check that the fault is no longer present | End of diagnosis | |||