System description System description EDC M(S) 5 Engine speed 1 Engine speed 2 Boost pressure Coolant temperature Charge air intake temperature Drive stage selection EHAB Electrohydraulic cut-out Control unit Intermediate engine speeds Power supply terminal 30 Terminal 15 PWM signal ISO diagnosis Diagnosis request Diagnosis warning lamp CAN bus Engine speed The controller contains the linear solenoid the control rod position transducer The linear solenoid is actuated by the electronic control unit.
The control unit processes information which it receives via the control rod position transducer the drive position selection drive stage selection coolant temperature sensor charge-air temperature sensor intermediate engine speed setpoint and the rpm sensors. The diagnosis request push button and the EDC indicator lamp are used in detecting faults and signalling them through a code. An ISO interface provides a communication with the MAN-cats test and diagnostic computer. The control unit, with its program adapted to the engine model concerned, determines the optimum setting of the control rod from all the measured values.
To ensure the vehicle can still be driven to the nearest workshop in the event of one or several sensors fail- ing, an emergency drive function is integrated in the control unit which, depending on the situation, makes it possible to continue driving with restricted functions. When the brakes are applied, the system operates as an intermediate engine speed controller with a cyclic irregularity (P-degree) of 0, i.e. a set intermediate engine speed is maintained exactly provided the engine develops sufficient power output for this purpose. 7