Warning: Due to the high voltages produced by (/re electronic ignition system, extreme care must be taken when working on the system with the ignition switched on. Persons with surgically-implanted cardiac pacemaker devices should keep well clear of the ignition circuits, components and test equipment.
1 If a fault appears in the engine management (fuel injection/ignition) system of Fiat Punto first ensure that the fault is not due to a poor electrical connection or poor maintenance; i.e., check that the air cleaner filter element is clean, the spark plugs are in good condition and correctly gapped, that the engine breather hoses are clear and undamaged. On SOHC (8-valve) engines, also check that the accelerator cable is correctly adjusted. If the engine is running very roughly, check the compression pressures and the valve clearances.
2 If these checks fail to reveal the cause of the problem, the vehicle should be taken to a suitably-equipped Fiat dealer for testing. A diagnostic connector is incorporated in the engine management wiring circuit into which a special electronic diagnostic tester can be plugged. The tester will locate the fault quickly and simply alleviating the need to test all the system components individually which is a time-consuming operation that carries a high risk of damaging the ECU, 3 The only ignition system checks which can be carried out by the home mechanic, relating to the spark plugs, and the ignition coil test, if necessary, the system wiring and wiring connectors can be checked, ensuring that the ECU wiring connectors of Fiat Punto have first been disconnected.