Special injectors with hydraulic servo-system and electrical triggering (solenoid valve) are used with common rail system in order to archieve efficient start of injection and precise injected fuel quantity. The nozzle has opened by the electrical pulse, the energizing current is reduced to a lower holding value. The Injection is terminated when the solenoid valve is no longer triggered and closes as result. The switching on the ECM, the current profile of the injector with booster, clear, and recharge phases is the following step. Capacitor in ECM is function to charge for activating the injectors
① Capacitor discharge -> ② Pull up current -> ③ Charge (7A) -> ④ Hold in current (12±1A) -> ⑤ Charge (⑥,⑦ Hold in control current)
The ECM will set a code if an error is detected in the ECM’s capacitor voltage malfunction during two driving cycles.
DTC NO. | Detecting Condition | Possible Cause |
P 1646 P 1647 | ● P 1646 Error is recognized if the voltage of injector booster capacitor is above 95V continously two times ● P 1647 Error is recognized if the voltage of injector booster capacitor is below 10V from the standard voltage according to the battery voltage and recharging time ● Engine Condition : RUN ● Fuel Limit : NO ● Fuel Cut : YES ● EGR OFF : NO ● MIL : NO | ECM |
