DTC P1093 (Flash Code 227) Fuel Rail Pressure (FRP) Too Low (RZ4E-TC)

1. DTC P1093 description

A typical common rail (fuel rail) system is composed of the following 2 fuel pressure sections. A suction side between the fuel tank and the fuel supply pump and a high-pressure side between the fuel supply pump and the injectors. The fuel is drawn from the fuel tank and then pumped into the fuel rail by 2 plungers that are located inside the fuel supply pump. The fuel rail pressure is regulated through the ECM's control of the FRP regulator based on signals from the FRP sensor. If the ECM detects that the actual fuel rail pressure is lower than the desired fuel rail pressure, the DTC is set.

2. Condition for setting DTC P1093

Condition for running the DTC

The battery voltage is 9 to 16 V.
The ignition voltage is 9 to 16 V.
The ignition switch is ON.
The engine coolant temperature is -40℃ {-40°F} or more.
The intake air temperature is -0.1°C {32°F} or more.
The engine is running.
Rail pressure feedback mode is active.
DTCs P0087, P0112, P0113, P0182, P0183, P060B, P0651, and P1655 are not set.

Refer to "51.Engine Control 1A.Troubleshooting(RZ4E-TC) DTC P0087 (Flash Code 225) Fuel Rail/System Pressure - Too Low".

Refer to "51.Engine Control 1A.Troubleshooting(RZ4E-TC) DTC P0112 (Flash Code 22) Intake Air Temperature Sensor Circuit Low".

Refer to "51.Engine Control 1A.Troubleshooting(RZ4E-TC) DTC P0113 (Flash Code 22) Intake Air Temperature Sensor Circuit High".

Refer to "51.Engine Control 1A.Troubleshooting(RZ4E-TC) DTC P0182 (Flash Code 211) Fuel Temperature Sensor Circuit Low".

Refer to "51.Engine Control 1A.Troubleshooting(RZ4E-TC) DTC P0183 (Flash Code 211) Fuel Temperature Sensor Circuit High".

Refer to "51.Engine Control 1A.Troubleshooting(RZ4E-TC) DTC P060B (Flash Code 36) Internal Control Module A/D Processing Performance".

Refer to "51.Engine Control 1A.Troubleshooting(RZ4E-TC) DTC P0651 (Flash Code 56) Sensor Reference Voltage 2 Circuit".

Refer to "51.Engine Control 1A.Troubleshooting(RZ4E-TC) DTC P1655 (Flash Code 59) Sensor Reference Voltage 4 Circuit".

Condition for setting the DTC

The ECM detects that the actual fuel rail pressure is less than the desired fuel rail pressure by the predetermined value or more for 5.1 seconds or more.

3. Action taken when DTC P1093 sets

Euro4: The ECM illuminates the MIL. Refer to Action taken when DTC sets - Type B (Euro4).
Except Euro4: The ECM illuminates the check engine warning light. Refer to Action taken when DTC sets - Type B (Except Euro4).

Refer to "51.Engine Control 1A.Troubleshooting(RZ4E-TC) DTC type definitions".

The ECM inhibits pre-injection.

4. Condition for clearing DTC P1093

Euro4: Refer to Condition for clearing the MIL/DTC - Type A or Type B (Euro4).
Except Euro4: Refer to Condition for clearing the check engine warning light/DTC - Type A or Type B (Except Euro4).

Refer to "51.Engine Control 1A.Troubleshooting(RZ4E-TC) DTC type definitions".