DTC P0088 (Flash Code 118) Fuel Rail/System Pressure - Too High (RZ4E-TC)

1. DTC P0088 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 fuel pressure is excessively high for a predetermined period of time, the DTC is set. When the ECM detects fuel pressure even higher than the needed amount for a predetermined period of time during the same ignition cycle, the MIL illuminates. When the MIL illuminates, this means that the fuel pressure has become excessively high but the pressure limiter either is not operating or is not operating quickly enough.

2. Condition for setting DTC P0088

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.
  • Rail pressure feedback mode is active.
  • DTCs P0192, P0193, P060B, and P0651 are not set.

Refer to "51.Engine Control 1A.Troubleshooting(RZ4E-TC) DTC P0192 (Flash Code 245) Fuel Rail Pressure Sensor Circuit Low".

Refer to "51.Engine Control 1A.Troubleshooting(RZ4E-TC) DTC P0193 (Flash Code 245) Fuel Rail Pressure 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".

Condition for setting the DTC

  • The ECM detects that the fuel rail pressure is the predetermined value or more for 2 seconds or more.

3. Action taken when DTC P0088 sets

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

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

  • The ECM limits the fuel injection quantity.
  • The ECM inhibits pre-injection.
  • The ECM inhibits the turbocharger control.
  • The ECM inhibits the cruise control.

4. Condition for clearing DTC P0088

  • 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".

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