Powertrain Management: Description and Operation

ENGINE MANAGEMENT SYSTEM
Description
The engine management system (EMS) maintains optimum engine performance over the entire operating range. The correct amount of fuel is metered into each cylinder inlet tract and the ignition timing is adjusted at each spark plug.
The system is controlled by the Engine Control Module (ECM) which receives data from sensors located on and around the engine. From this information it provides the correct fuel requirements and ignition timing to suit all engine loads and speeds.
The fuel injection system uses a hot wire Mass Air Flow sensor to calculate the amount of air flowing into the engine.
The ignition system does not use a distributor. It is a direct ignition system (DIS), using four double ended coils. The circuit to each coil is completed by switching inside the ECM.
The on board diagnostic system detects any faults which may occur within the EMS. Fault diagnosis includes failure of all EMS sensors and actuators, emissions related items, fuel supply and exhaust systems.
The system incorporates certain default strategies to enable the vehicle to be driven in case of sensor failure. This may mean that a fault is not detected by the driver. The fault is indicated by illumination of the malfunction indicator light (MIL).