Controles eletrônicos do motor – Funcionamento do sistema e componentes

Electronic Engine Controls – 2.5L Duratec-HE (122kW/165PS) 303-14A- 303-14A- - MI4 DESCRIPTION AND OPERATION On vehicles without a CMP sensor, cylinder no. 1 is recognized using the different current rises of the two sparked cylinders 1 and 3. Engine oil pressure (EOP) sensor E135527 The EOP switch detects the oil pressure. When a defined engine oil pressure is reached, the EOP switch opens. This information is transmitted via the CAN bus to the instrument cluster where the EOP warning lamp is switched on or off accordingly. Knock (KS) sensor E135528 The knock sensors are piezo-ceramic sensors that allow the ECM to employ active knock control and prevent engine damage from pre-ignition or detonation. Two knock sensors are installed on the inboard side of each cylinder head, one mid-way between cylinders 1 and 2, and one mid-way between cylinders 3 and 4. Each knock sensor is secured with a single screw. On each knock sensor, a two pin electrical connector provides the interface with the engine harness. The ECM compares the signals from the knock sensors with mapped values stored in memory to determine when detonation occurs on individual cylinders. When detonation is detected, the ECM retards the ignition timing on that cylinder for a number of engine cycles, then gradually returns it to the original setting. The ECM cancels closed loop control of the ignition system if the signal received from a knock sensor becomes implausible. In these circumstances the ECM defaults to base mapping for the ignition timing. This ensures the engine will not become damaged if low quality fuel is used. The MIL will not illuminate, although the driver may notice that the engine 'pinks' in some driving conditions and displays a drop in performance and smoothness. The ECM calculates the default value if one sensor fails on each bank of cylinders. Injectors E135529 The electromagnetically controlled injectors dose and atomize the fuel. The quantity of injected fuel is regulated by the duration of actuation of the fuel injectors. The fuel injectors are either closed (not actuated) or opened (actuated). Each cylinder has its own injector. The injection is accurately dosed and takes place at a time determined by the PCM. Injection takes place immediately in front of the intake valves of the cylinder.