Description General The Td6 engine has an Electronic Diesel Control (EDC) engine management system. The system is controlled by an Engine Control Module (ECM) and is able to monitor, adapt and precisely control the fuel injection. The ECM uses multiple sensor inputs and precision control of actuators to achieve optimum performance during all driving conditions. The ECM controls fuel delivery to all six cylinders via a Common Rail (CR) injection system. The CR system uses a fuel rail to accumulate highly pressurised fuel and feed the six, electronically controlled injectors. The fuel rail is located in close proximity to the injectors, which assists in maintaining full system pressure at each injector at all times. The ECM uses the drive by wire principle for acceleration control. There are no control cables or physical connections between the accelerator pedal and the engine. Accelerator pedal demand is communicated to the ECM by two potentiometers located in a throttle position sensor. The ECM uses the two signals to determine the position, rate of movement and direction of movement of the pedal. The ECM then uses this data, along with other engine information from other sensors, to achieve the optimum engine response. The ECM also controls the Exhaust Gas Recirculation (EGR) system which is fitted to reduce the formation of oxides of nitrogen (NO x ). This group of gases is formed in the combustion chamber under conditions of high temperature and high pressure. It is not desirable to reduce the compression ratio, so the ECM reduces the combustion temperature by introducing a controlled volume of inert gas into the cylinders on the induction stroke. The inert gas used is exhaust gas, which is freely available. It is directed from the exhaust manifold, via a control valve, into the intake manifold. The flow of gas is monitored by the ECM using a Mass Air Flow (MAF) sensor. The EGR system is not required until the engine is hot, and is turned off during engine idling and wide open 'throttle' to preserve smooth operation and driveability. The ECM processes information from the following input sources: l Brake switch l Crankshaft Position (CKP) sensor l Camshaft Position (CMP) sensor l Anti-lock Brake System (ABS) ECU l Engine Coolant Temperature (ECT) sensor l Boost Pressure (BP) sensor l Low side fuel pressure sensor l Accelerator Pedal Position (APP) sensor l Mass Air Flow/Intake Air Temperature (MAF/IAT) sensor l Fuel rail pressure sensor l Controller Area Network (CAN) l Glow plug relay l Immobilisation ECU. The ECM outputs controlling signals to the following sensors and actuator: l Fuel injector solenoids l Boost control solenoid valve l Exhaust Gas Recirculation (EGR) actuator l Engine mount damping control actuator l Glow plug relay l Rail pressure control valve l Electric cooling fan control l Automatic Temperature Control (ATC) ECU.
ENGINE MANAGEMENT SYSTEM – TD6 DESCRIPTION AND OPERATION 18-1-11