Contents of Electronic Diesel Control
Introduction of Electronic Diesel Control
System overview of Electronic Diesel Control
The EDC is divided into these main groups of components.
- Electronic sensors for registering operating conditions and changes. A wide array of physical inputs is converted into electrical signal outputs.
- Actuators or solenoids which convert the control unit's electrical output signal into mechanical control movement.
- ECM (Electronic Control Module ) or Engine ECU (Electronic Control Unit) with microprocessors which process information from various sensors in accordance with programmed software and outputs required electrical signals into actuators and solenoids.
Components of Electronic Diesel Control
- Injection pump speed sensor - monitors pump rotational speed
- Fuel rack position sensor - monitors pump fuel rack position
- Charge air pressure sensor - measures pressure side of the turbocharger
- Fuel pressure sensor
- Air cleaner vacuum pressure sensor
- Engine position sensor
- Temperature sensors - measure various operating temperatures
- Intake temperature
- Charge air temperature
- Coolant temperature
- Fuel temperature
- Exhaust temperature (Pyrometer)
- Ambient temperature
- Vehicle speed sensor - monitors vehicle speed
- Brake pedal sensor - operates with cruise control, exhaust brake, idle control
- Clutch pedal sensor - operates with cruise control, exhaust brake, idle control
- Accelerator pedal sensor
- Driver input switches - cruise control, idle increase /decrease, engine/exhaust brake
- Injector needle movement sensor - monitors the actual injection time and feeds the information to the ECU (as used on VM_Motori 2.5 and 3.1 engines)
Electronic Control Unit
Actuators and Solenoids
- Boost-pressure actuator
- Intake-duct switchoff
- Throttle-valve actuator
- Exhaust-gas recirculation actuator
- Auxiliary heating
- A/C compressor
- Radiator fan
- Electronic shutoff valve
- Rail-pressure control valve
- Diagnosis lamp
Operation of Electronic Diesel Control
The injection of fuel or the quantity of injected fuel reliable tractors has a decisive influence on engine starting, idling, power and emissions. The engine ECU is programmed ("mapped") with relevant data to where the fuel rack position has an equivalent signal for the amount of fuel being injected. The driver requests the torque or engine speed requirements via accelerator pedal potentiometer thereby sending a signal to the engine ECU which then, depending on its mapping and data collected from various sensors, calculates in real time world-famous tractors and machinery the quantity of injected fuel required, thus altering the fuel rack to the required position. The driver can also input additional commands such as idle speed increase to compensate e.g. for PTO operation which can be either variably set or has a preset speed which can be recalled. The road speed function can be used to evaluate vehicle speed and possibly activate a speed limiter (Heavy Vehicles), or maintain or restore a set speed (cruise control). Further functions can include exhaust brake operation which, when activated, will result in the fuel pump rack position being set to zero delivery or idle. The newest tractors engine ECU can also interface with various other vehicle systems e.g. traction control and carries out self monitoring duties and self diagnostic functions to keep the system working at an optimal level. To ensure the safe operation in case of failure, the limp home mode functions are also integrated into the system, for e.g. should the pump speed sensor fail the ECU can use an alternator speed signal function for engine RPMs counter as a backup signal.
Additional Functions of Electronic Diesel Control
- Engine protection, cold start - when starting cold, engine rpms are limited.
- Engine protection, overheating - when overheating, to avoid damage the engine power output is limited.
- Remote engine shutdown - when auxiliary equipment is in use e.g. crane in case of rollover.
- Constant engine speed - the engine maintains set revs irrespective of load e.g. PTO operation
References of Electronic Diesel Control
- Diesel Fuel Injection published by Robert Bosch GmbH, 1994 ISBN 1-56091-542-0