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Control Module (ECM) uses the Fuel Rail Pressure (FRP) sensor to determine fuel pressure to the fuel injectors. This is then compared to the calculated target fuel pressure as determined by the ECM. The ECM adjusts the FRP by modulating the duty cycle of the control driver of the fuel pressure regulator. Injector pulse duration is determined by the measured rail pressure and the target injection fuel into each cylinder. If a sensor circuit malfunction is detected, or the commanded fuel injection pump flow is not within the proper range for a given engine load and speed, DTC will be set.
Conditions For Setting DTC
The difference between commanded fuel pressure and actual fuel pressure is more than 20 MPa; or the FRP Regulator Fuel Flow is more than 15,000 mm3 at 800 RPM, or more than 38,000 mm3 at 2000 RPM.
Conditions For Running DTC
DTCs P0192, P0193 or P1635 are not set.
The ignition is ON.
This DTC does not set for an idle condition.
A number of conditions may cause DTC P0087 and DTC P1093 to set:
Excessive fuel return to the tank.
A fuel injection pump failure.
A fuel pressure regulator failure.
If you have to prime the fuel system, check for the following conditions:
A restricted fuel supply line.
A fuel supply line air leak.
A sticking Fuel Pressure Regulator may set this DTC.