P0087

CIRCUIT DESCRIPTION
The engine control module (ECM) monitors fuel rail pressure (FRP) using the FRP sensor. If the sensor indicates a pressure less than the commanded rail pressure plus a possible transitional overshoot, the ECM will set diagnostic trouble code (DTC) P0087 for fuel rail pressure too low.

CONDITIONS FOR RUNNING THE DTC
^ DTCs P0192, P0193, or P1635 are not set.
^ The ignition is ON.

CONDITIONS FOR SETTING THE DTC
The actual FRP is less than 0.0 MPa at 0-400 RPM.

OR

The actual FRP is less than 22.5 MPa at more than 600 RPM.

ACTION TAKEN WHEN THE DTC SETS
^ 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. The control module stores this information in the Freeze Frame/Failure Records.
^ The ECM will limit fuel injection.

CONDITIONS FOR CLEARING THE MIL/DTC
^ 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.

DIAGNOSTIC AIDS
A restricted fuel supply line may cause DTCs P0087 and P1093 to set at the same time. Refer to Fuel System Diagnosis (Single Tank) or Fuel System Diagnosis (Dual Tanks). Component Tests and General Diagnostics

TEST DESCRIPTION

DTC P0087 - Steps 1-10:

DTC P0087 - Steps 11-17:

The numbers below refer to the step numbers on the diagnostic table.
2. If the fuel temperature is high enough to set DTC P0168, the fuel may be thin enough to cause this DTC to set.
3. The engine will not start if the fuel leak is large enough.
4. This step checks for an inaccurate fuel rail pressure sensor.
5. This step checks for a restriction in the fuel system between the fuel injection pump and the fuel tank.
6. This test checks to see if the fuel injection pump is able to supply maximum fuel pressure at idle. The fuel injection pump should be able to create 145-158 MPa at idle. If the test is performed in extreme ambient temperatures, the fuel pressure will still be more than 145 MPa.
7. This step checks for a restriction in the fuel system between the fuel injection pump and the fuel tank that may only cause symptoms at higher engine speed and load conditions.
9. This step checks to see if the fuel rail pressure sensor wiring and ECM are functioning normally.
11. If the vacuum is still too high in the fuel supply system after replacing the fuel filter, there is a restriction in the fuel supply lines or sending unit in the fuel tank.