Test results

Check the following, in order:

- presence of fuel in the tank;

- engine control unit correctly fastened to earth;

- battery correctly fastened to earth;

- positive battery terminal and all leads connected to it correctly fastened

- that there are no impurities/water in the fuel tank - no obstructions in the air intake circuit

Go to Step 1

No fuel

Add fuel to the tank

Fastening slack or oxidized

Restore correct fastenings

Presence of dirt in the fuel tank

Add fuel to the tank

Circuit obstructed

Clean the tank and pipes and replace the filter element

Connect the diagnosis equipment (Examiner or other instruments) to the diagnosis socket and check:

- that there are no errors in the control unit;

- parameter plausibility

Go to Step 2

Error detected in the control unit

Continue following the instructions on the diagnostic equipment

Impossible to activate a dialogue with the control unit

Go to Step 2

Check that the engine control unit is receiving the correct power supply

Check the continuity of the power supply wiring

Check the continuity of the engine compartment junction unit fuses

Go to Step 3

Main relay defective

Replace the relay

Control unit power supply wiring defective

Restore correct wiring.

Power supply fuses blown

Replace the blown fuses after having ascertained the cause of the malfunction.

Carry out a road test reproducing the conditions in which the fault occurs, keeping the diagnostic equipment connected and check:

- that there are no errors in the control unit;

- parameter plausibility

Go to Step 4

Sudden onset of errors in the control unit detected

Continue following the instructions on the diagnostic equipment

Parameters off the scale.

Continue following the instructions on the diagnostic equipment

Loss of dialogue between the control unit and the diagnostic equipment.

Restore the correct connections.

Check the continuity of the power supply wiring

Check the operation of the ignition coils by carrying out

 See Test 5510CI CHECK ON OPERATION OF IGNITION COILS

Go to Step 5

Power supply wiring to coils broken

Restore correct wiring.

Defective coils.

Replace coils

 Op. 5510C14 IGNITION COIL/S - R.R.

Check the continuity of the power supply wiring

 See E5030 PETROL ENGINES ELECTRONIC MANAGEMENT

Go to Step 6

Injector supply wiring interrupted

Restore correct wiring.

Carry out a road test and check the fuel supply pressure in the conditions in which the problem occurs.

Check that the fuel lines are not blocked by carrying out the

 See Test 1056BY FUEL SYSTEM SUPPLY PRESSURE CHECK

Check that the fuel pump is working properly by carrying out the

 See Test 1040AA CHECK ON POWER SUPPLY VOLTAGE AND CURRENT UPTAKE

Go to Step 7

Fuel pressure too low: pipes obstructed

Eliminate the constrictions, replace the pipes if necessary

Fuel pressure too low: pump defective.

Replace the fuel pump assembly

 Op. 1040A70 SUBMERGED PUMP ASSEMBLY COMPLETE WITH LEVEL GAUGE CONTROL - R + R

Check that the engine control unit is working properly.

End of diagnosis

Engine management control unit defective.

Replace the engine management control unit

 Op. 1056B82 INJECTION/IGNITION SYSTEM E.C.U. (ONE) - R + R