b. Pressure Limiter ‡ The pressure limiter opens to release the pressure if an abnormally high pressure is generated. ‡ When the rail pressure reaches approximately 200 MPa (2038 kg/cm 2 ), it trips the pressure limiter (the valve opens). When the pressure drops to approximately 50 MPa (509.5 kg/cm 2 ), the pressure limiter returns to its normal state (the valve closes) in order to maintain the proper pressure. ,/14E OKGQ ,/14E OKGQ :EPZI3TIR :EPZI'PSWI 14EOKGQ 5) c. Pressure Sensor ‡ The rail pressure sensor (Pc sensor) is attached to the rail in order to detect the fuel pressure.
‡ It is a semiconductor type pressure sensor that utilizes the characteristics of silicon, whereby the electrical resistance changes when pressure is applied to it. : : ' : 398 +2( : 14EOKGQ 5) It is necessary to reset the ECU default value using the ISUZU diagnosis tool at the time of supply pump service replace- ment. In addition, the ECU has a function enabling it to learn the performance of the supply pump at the time of ECU service replacement, so ensure sufficient time (several minutes) is available. -17-