199002952 - D001 ENGINE NOT RUNNING SMOOTHLY / (HESISTANT)

There is a (prolonged) drop in performance (flat spots) during acceleration
Test results
0PRELIMINARY CHECKSAll OKProblems encounteredOperation
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 batteryMove on to Step 1Air intake circuit faultyRestore the seal on the air intake circuit
Control unit motor earth connection on the engine block is defectiveRestore the correct earth connection
Loose cables to the batteryRestore correct tightening
1CHECK USING DIAGNOSTIC EQUIPMENTAll OKProblems encounteredOperation
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 plausibilityMove on to Step 2Error detected in the control unitContinue following the instructions on the diagnostic equipment
Parameter not consistentContinue following the instructions on the diagnostic equipment
2SHUT OFF BYPASS AIR SOLENOID VALVE CHECKAll OKProblems encounteredOperation
Check that the solenoid valve is working properly by carrying out the    See Test Move on to Step 3Solenoid valve stuck openReplace the by-pass solenoid valve    Op. 1048B58 TURBOCHARGER AIR BY-PASS VALVE - R.R.
Wiring from engine control unit to solenoid valve defectiveRestore correct wiring
Signal from engine control unit not correctReplace the engine control unit    Op. 1056B82 INJECTION/IGNITION SYSTEM E.C.U. (ONE) - R + R
3FUEL PRESSURE CHECKAll OKProblems encounteredOperation
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 CHECKMove on to Step 4Pressure not correct: obstructions in the fuel supply pipeRemove the obstructions in the fuel pipe, replace it if necessary
Pressure not correct: tank not sufficiently ventilatedRestore correct tank ventilation
Pressure not correct: petrol pump damagedReplace the petrol pump assembly    Op. 1040A70 SUBMERGED PUMP ASSEMBLY COMPLETE WITH LEVEL GAUGE CONTROL - R + R
4AIR/TEMPERATURE PRESSURE SENSOR CHECKAll OKProblems encounteredOperation
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 unitMove on to Step 5Wiring between sensor and engine control unit with short circuit or open circuitRestore correct wiring.
Sensor defectiveReplace the sensor    Op. 1056B54 INTAKE AIR PRESSURE/TEMPERATURE SENSOR - R.R.
5TURBOCHARGING PRESSURE SENSOR CHECKAll OKProblems encounteredOperation
Check correct operation of the pressure sensor by carrying out the    See Test 1064BA SUPERCHARGING PRESSURE CHECKCheck the continuity/insulation of the wiring between the sensor and the engine control unitMove on to Step 6Wiring between sensor and engine control unit with short circuit or open circuitRestore correct wiring.
Sensor defectiveReplace the pressure sensor    Op. 1056B44 AIR PRESSURE SENSOR - R.R.
6CANISTER SOLENOID VALVE CHECKAll OKProblems encounteredOperation
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 7Defective solenoid canisterReplace canister solenoid valve    Op. 1080E28 ENABLEMENT SOLENOID FOR FLOW OF FUEL VAPOUR TO INLET - R+R
Wiring brokenRestore correct wiring
7CORRECT OPERATION CHECKAll OKProblems encounteredOperation
Check that the fault is no longer presentEnd of diagnosisThe fault persistsReplace the engine management control unit    Op. 1056B82 INJECTION/IGNITION SYSTEM E.C.U. (ONE) - R + R