Important: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance |
---|---|---|---|---|---|
FRP Sensor 5-Volt Reference | P0117, P0522, P0652, P0700 | P0087, P0191, P0192, P0700 | P0193 | P0533, P0653 | -- |
FRP Sensor Signal | P0192 | P0191 | P0193 | P0193 | -- |
Fuel Pressure Regulator Solenoid Supply Voltage | P0090 | P0088 | P0090 | P0087, P0191, P2510 | -- |
Fuel Pressure Regulator Solenoid Control | P0088, P0090 | P0088 | P0090 | P0090 | -- |
The fuel injection pump supplies high pressure fuel to the fuel injection rails, and then to the fuel injectors through high pressure pipes. The fuel rail pressure (FRP) sensor is a three wire sensor mounted in the right fuel injection rail. The FRP sensor uses a 5-volt reference circuit , a signal circuit, and a low reference circuit to monitor fuel rail pressure. This information is sent to the engine control module (ECM) to assist in the fueling of the engine.
• | DTCs P0090, P0192, P0193 are not set. |
• | The engine is running. |
• | DTCs P0087, P0192, P0193 are not set. |
• | The engine is running. |
• | The actual FRP is more than 20 MPa (2,900 psi) below the desired FRP. |
OR |
• | The actual FRP is less than 22.5 MPa (3,263 psi). |
• | The actual FRP is more than 20 MPa (2,900 psi) above the desired FRP. |
OR |
• | The actual FRP is more than 189 MPa (27,412 psi) |
The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails. The control module records the operating conditions at the time the diagnostic fails and stores this information in the Freeze Frame/Failure Records. The ECM will limit fuel injection.
• | The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail. |
• | A current DTC, Last Test Failed, clears when the diagnostic runs and passes. |
• | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic. |
• | Clear the MIL and the DTC with a scan tool. |
• | Gasoline contamination of the fuel may cause this DTC to set. Refer to Contaminants-in-Fuel Diagnosis . |
• | When ambient temperatures are below 0°C (32°F), the fuel tank pickup screen may be iced over from water in the fuel tank. |
• | When power enhancing devices have been attached to the fuel rail pressure sensor circuits, this DTC may set and adversely effect the fuel system components. |
• | If the fuel pressure valve is not torqued correctly, the valve will leak fuel into the fuel return system causing this DTC to set. The fuel pressure relief valve uses a bite type seal, and proper torque is essential for valve to rail sealing. Refer to Fastener Tightening Specifications . |
• | A sticking FRP regulator may cause this DTC to set. |
• | High fuel injector return flow may cause this DTC to set. |
• | The addition of fuel system enhancements, such as auxiliary fuel tanks or add on fuel filters may relate to driveability complaints. |
• | Driveability concerns may not occur with this DTC present. |
• | If the fuel system pressure is actually too high, a fuel knock and smoke condition will exist. |
• | A sticking FRP regulator may cause this DTC to set. |
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
J 44638 Vacuum Gage
With engine running, observe the Actual Fuel Rail Pressure parameter with a scan tool. A normal reading would be approximately 40 MPa (5,802 psi) with the engine cold, and 30 MPa (4,351 psi) at operating temperature. Inspect the fuel supply lines for damage between the fuel tank and the fuel injection pump.
⇒ | If greater than the specified range, replace the ECM. |
Important: Ensure that the transmission is in Park or Neutral with the parking brake set.
⇒ | If the engine does not start, refer to Engine Cranks But Does Not Run . |
⇒ | If more than 5 inches Hg of vacuum was present during engine speed increase, replace the fuel filter and inspect for fuel system restrictions. |
⇒ | If the Actual Fuel Rail Pressure is less than 145 MPa (21,030 psi), refer to Fuel System Diagnosis - High Pressure Side . |
Important: If the fuel temperature is near 121°C (250°F) during the duplication of the complaint, or in the Failure Records for this DTC, inspect for a restriction in the fuel cooler air flow or the fuel heater always ON. Refer to Fuel Heater Always On .
⇒ | If the vacuum was more than 12 inches Hg of vacuum at any time in the operating range, inspect for kinked or restricted fuel supply lines. |
⇒ | If the Actual Fuel Rail Pressure is less than the Desired Fuel Rail Pressure, refer to Fuel System Diagnosis - High Pressure Side . |
⇒ | If fuel system tests normal, refer to Diagnostic Aids. |
⇒ | If the pressure difference between the actual and desired pressure are more than 2 MPa (290 psi), replace the fuel pressure regulator. |
⇒ | If all circuits test normal, refer to Diagnostic Aids |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.