Fuel Delivery Pressure Sensor Circuit – Voltage Below Normal, or Shorted to Low Source
|Fault Code: 547
Fuel Delivery Pressure Sensor Circuit – Voltage Below Normal, or Shorted to Low Source. Low signal voltage or an open circuit detected at the rail fuel pressure circuit.
Engine may not start, may have low power, white smoke, or run rough.
ISX – Fuel Delivery Pressure Sensor
The fuel delivery pressure sensor responds to pressure changes in the fuel manifold of the integrated fuel system module. The fuel delivery pressure sensor has a 5 VDC supply circuit, a sensor signal voltage, and a return circuit.
The electronic control module (ECM) provides a 5 VDC supply to the fuel delivery pressure sensor using a common sensor supply circuit. The ECM also provides a ground on the sensor return circuit. The fuel delivery pressure sensor provides a signal to the ECM on the fuel delivery pressure sensor signal circuit. This sensor signal voltage changes based on the pressure in the fuel manifold. The ECM will detect a high signal voltage during high engine load operating conditions.
The rail fuel pressure sensor is located on the bottom front corner of the integrated fuel system module. Refer to Procedure 100-002 (Engine Diagrams) in Section E for a detailed component location view.
Conditions for Running the Diagnostics
This diagnostic runs continuously when the keyswitch is in the ON position.
Conditions for Setting the Fault Codes
The ECM detects that the fuel delivery pressure signal voltage is less than 0.34 VDC for more than one second.
Action Taken When the Fault Code is Active
- The ECM illuminates the amber CHECK ENGINE light immediately when the diagnostic runs and fails.
- A default value for the fuel delivery pressure reading is used.
Conditions for Clearing the Fault Code
The ECM will turn off the amber CHECK ENGINE light immediately after the diagnostic runs and passes.
Verify the electronic control module (ECM) calibration is correct. Check the calibration revision history found on QuickServe® Online for applicable fixes to the calibration stored in the ECM. If necessary, recalibrate the ECM. Refer to Procedure 019-032 (ECM Calibration Code) in Section 19 in the corresponding Troubleshooting and Repair Manual for the engine being serviced.
The rail fuel pressure sensor shares supply and return wires in the engine harness with other sensors. Opens and shorts in the engine harness can cause multiple fault codes to be active. Before troubleshooting Fault Code 547, check for multiple faults.
Possible causes of this fault code include:
- Open signal circuit in the engine harness, connectors, or sensor.
- Signal circuit shorted to ground in the engine harness, connector, or sensor.
- Failed sensor.