Check the following, in order:

• engine control unit correctly fastened to earth;

See E5030 PETROL ENGINES ELECTRONIC MANAGEMENT

• battery correctly fastened to earth;
• positive battery terminal and all leads connected to it correctly fastened
• correct connection of the engine control unit connector

1. Battery fastenings slack or oxidized

2. Control unit earth cable fastening loose

3. Incorrectly connected engine control unit connector

1. Restore correct fastenings

2. Tighten earth cable

3. Correctly engage engine control unit connector

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

• that there are no errors in the control unit;
• parameter plausibility

1. Error detected in the control unit.

2. Impossible to activate a dialogue with the control unit

1. Continue following the instructions on the diagnostic equipment

2. Move on to Step 2

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

1. The sudden onset of errors in the control unit is detected

2. Parameters off the scale.

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

1. Continue following the instructions on the diagnostic equipment

2. Continue following the instructions on the diagnostic equipment

3. Restore the correct connections.

Check the continuity of the supply wiring for the coils

Check that the ignition coils are working, by carrying out the

See Test 5510CI IGNITION COIL OPERATION CHECK

, the

See Test 5510CE IGNITION CONTROL SIGNAL CHECK

and the

See Test 5510OA IGNITION COIL RESISTANCE CHECK

1. Power supply wiring to coils defective

2. Defective coils.

1. Restore correct wiring

2. Replace coils

Op. 5510D10 SPARK PLUGS - R+R

Check the continuity of the supply wiring

See E5030 PETROL ENGINES ELECTRONIC MANAGEMENT

Replace the engine management control unit

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

Check that the air intake/vacuum circuit is working properly

Check the condition of the fuel supply circuit and make sure that it is working properly.

Also check:

• wiring on engine correctly fastened to earth;
• battery correctly fastened to earth;
• positive battery terminal and all leads connected to it correctly fastened

1. Supply fastenings slack or oxidized

2. Earth fastenings slack or oxidized

1. Restore correct fastenings

See E1010 POWER SUPPLY

2. Restore correct fastenings

See E1010 POWER SUPPLY

Check that the diesel leaks from the injector recirculation connections are small (seepage) and roughly equal to one another, carrying out the

See Test 1060OC INJECTOR SEAL TEST

Replace the injector

Op. 1060F10

Check that the high pressure diesel parameter is correct, carrying out the

See Test 1060OD HIGH PRESSURE FUEL CIRCUIT CHECK

Check that the pressure in the return pipe to the tank is correct, carrying out the

See Test 1060OA LOW FUEL RETURN PRESSURE CIRCUIT CHECK

Check that the diesel pressure between the filter and the pressure pump is correct, carrying out the

See Test

Replace the fuel filter cartridge

Op. 1044B10 FUEL FILTER ASSEMBLY - R + R OR REPLACE

Check that the supply pump pressure at the filter inlet is correct, carrying out the

See Test 1060OB LOW FUEL DELIVERY PRESSURE CIRCUIT CHECK

Check that the pump power supply voltage is correct, as described in the

Check that the current uptake is correct, carrying out the

See Test 1040AA

1. Voltage lower than 12 V

2. Current greater than 10 A: pump defective

3. Current less than 2 A: pump obstructed

1. Renew electrical wiring

See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT

2. Replace the fuel pump

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

3. Replace the fuel pump

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

and clean the fuel tank

Replace the engine management control unit

Op. 1060G80 DIESEL ELECTRONIC INJECTION CONTROL UNIT - R.R