Test Undervoltage Flash code: 1x long, 3x short Fault indication: Fault is not indicated by EDC indicator lamp Fault path: Control unit power supply (battery voltage too low) Effect of fault: The EDC system or the engine can behave in various ways depending on the magnitude of the voltage drop: No power Highly irregular engine operation No engine operation Excessive smoke emission Contradictory fault code memory entries Possible cause Battery discharged or defective, alternator defective, line break, short-circuit, main relay defective Test precondition:
EDC control unit disconnected Socket box connected “Ignition” switched on 48 Test Measurement Corrective measures Power supply To activate the main relay, connect jumper across pin 46 and pin 19 Measure voltage at socket box across pin 15/16 (+) and pin 18/19 (–) Setpoint: 24–28 V – Check lines – Check plug connections – Replace main relay – Check battery, generator and circuit breaker F1 on engine