DTC | P1185 | Maximum Pressure Exceeded |
P1186 | Minimum Pressure at Engine Speed Too Low | |
P1187 | Regulator Valve Stick | |
P1188 | Leakage | |
P1189 | Governor Deviation at Engine Speed Too High |
The ECM determines the rail pressure value as a function of the engine’s operating conditions and controls the Fuel pressure regulator to ensure that the rail pressure reaches the required value. If the rail pressure is excessive, the Fuel pressure regulator opens and a portion of the fuel returns from the rail to the fuel tank via a collector line. If the rail pressure is too low, the Fuel pressure regulator closes. Fuel pressure regulator is installed in the tail end of high-pressure accumulator (rail).
DTC No | Detecting Condition & Limp Home | Suspected area |
P1185 P1186 P1187 P1188 P1189 | Detecting Condition P1185: The fuel pressure ＞ 1450 bar P1186: The fuel pressure measured is lower than the minimum pressure mapped at each engine speed. P1187: The duty value of Fuel pressure regulator is below 10% and Fuel pressure measured ＞ fuel pressure mapped + 250 bar P1188: The duty value of Fuel pressure regulator is over 79% and Fuel pressure measured + 250 bar ＜ fuel pressure mapped P1189: The fuel pressure measured dose not reach the appropriate rail pressure at each engine speed. Enable Condition Engine speed ＞ 700 rpm Limp Home None | - Fuel filter - Injector - Electric fuel pump - Rail pressure sensor - Fuel pressure regulator - High pressure pump - Fuel leakage in fuel supply system - ECM |
High Pressure Pump | Normal Parameter |
Engine idle state after engine warming up | |
Rail pressure | 220 ~ 300 bar (22 ~ 30 Mpa) |
Proceed with ECM problem procedure. |
