|  |  | Test results | 
| 0 | PRELIMINARY CHECKS | All OK | Problems encountered | Operation | 
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|  | First, check:- the condition of the air intake circuit- correct earth connection of the coils and the control unit motor to the engine block    See E5030  PETROL ENGINES ELECTRONIC MANAGEMENT - leads properly connected to battery | Move on to Step 1 | Air intake circuit faulty | Restore the seal on the air intake circuit | 
| Control unit motor earth connection on the engine block is defective | Restore the correct earth connection | 
| Loose cables to the battery | Restore correct tightening | 
| 1 | CHECK USING DIAGNOSTIC EQUIPMENT | All OK | Problems encountered | Operation | 
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|  | Connect the diagnostic equipment (Examiner or other instruments) to the diagnostic socket.Check:- that there are no faults in the engine management control unit;- parameter plausibility | Move on to Step 2 | Error detected in the control unit | Continue following the instructions on the diagnostic equipment | 
| Parameter not consistent | Continue following the instructions on the diagnostic equipment | 
| 2 | SHUT OFF BYPASS AIR SOLENOID VALVE CHECK | All OK | Problems encountered | Operation | 
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|  | Check that the solenoid valve is working properly by carrying out the    See Test | Move on to Step 3 | Solenoid valve stuck open | Replace the by-pass solenoid valve    Op. 1048B58 TURBOCHARGER AIR BY-PASS VALVE - R.R. | 
| Wiring from engine control unit to solenoid valve defective | Restore correct wiring | 
| Signal from engine control unit not correct | Replace the engine control unit    Op. 1056B82  INJECTION/IGNITION SYSTEM E.C.U. (ONE) - R + R | 
| 3 | FUEL PRESSURE CHECK | All OK | Problems encountered | Operation | 
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|  | Carry out a road test, reproducing the conditions in which the fault occurs.Check the fuel supply pressure by performing the    See Test 1056BY FUEL SYSTEM SUPPLY PRESSURE CHECKand the    See Test 1056BI FUEL SYSTEM RETURN PRESSURE CHECK | Move on to Step 4 | Pressure not correct: obstructions in the fuel supply pipe | Remove the obstructions in the fuel pipe, replace it if necessary | 
| Pressure not correct: tank not sufficiently ventilated | Restore correct tank ventilation | 
| Pressure not correct: petrol pump damaged | Replace the petrol pump assembly    Op. 1040A70  SUBMERGED PUMP ASSEMBLY COMPLETE WITH LEVEL GAUGE CONTROL - R + R | 
| 4 | AIR/TEMPERATURE PRESSURE SENSOR CHECK | All OK | Problems encountered | Operation | 
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|  | Check correct operation of the pressure sensor by carrying out the    See Test 1056BU CHECK ON OPERATION OF PRESSURE SENSOR AND/OR INTAKE AIR TEMPERATURE SENSORCheck the continuity/insulation of the wiring between the sensor and the engine control unit | Move on to Step 5 | Wiring between sensor and engine control unit with short circuit or open circuit | Restore correct wiring. | 
| Sensor defective | Replace the sensor    Op. 1056B54  INTAKE AIR PRESSURE/TEMPERATURE SENSOR - R.R. | 
| 5 | TURBOCHARGING PRESSURE	 SENSOR CHECK | All OK | Problems encountered | Operation | 
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|  | Check correct operation of the pressure sensor by carrying out the    See Test 1064BA TURBOCHARGING PRESSURE CHECKCheck the continuity/insulation of the wiring between the sensor and the engine control unit | Move on to Step 6 | Wiring between sensor and engine control unit with short circuit or open circuit | Restore correct wiring. | 
| Sensor defective | Replace the pressure sensor    Op. 1056B44 AIR PRESSURE SENSOR - R.R. | 
| 6 | CANISTER SOLENOID VALVE CHECK | All OK | Problems encountered | Operation | 
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|  | With the Examiner in active diagnosis, check that the solenoid canister is working properlyCheck continuity of wiring between engine control unit and solenoid canister    See E5030  PETROL ENGINES ELECTRONIC MANAGEMENT | Move on to Step 7 | Defective solenoid canister | Replace canister solenoid valve    Op. 1080E28  ENABLEMENT SOLENOID FOR FLOW OF FUEL VAPOUR TO INLET - R+R | 
| Wiring broken | Restore correct wiring | 
| 7 | CORRECT OPERATION CHECK | All OK | Problems encountered | Operation | 
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|  | Check that the fault is no longer present | End of diagnosis | The fault persists | Replace the engine management control unit    Op. 1056B82  INJECTION/IGNITION SYSTEM E.C.U. (ONE) - R + R |