New Holland ENG 547 – Engine Control Module (ECM): Fuel Pressure sensor voltage is too low.

The ECM detects that the signal voltage returning from the fuel rail pressure sensor has dropped below the normal operating range. This typically indicates a short to ground in the signal circuit, an open supply wire, or an internally failed sensor.

• T4 series
• T5 series
• T6 series
• T7 series
• T8 series
• T9 series
• T8000 series
• T6.140
• T7.200
• CR series
• CX series
• CR7090
• CR8090
• CR9090
• CX8090

1. 1

   Inspect the wiring harness and connector at the fuel rail pressure sensor for chafing, rubbing, or damaged wires (note that wires can break internally while insulation remains intact).

2. 2

   Disconnect the sensor and inspect the pins for corrosion, moisture, or pushed-back terminals.

3. 3

   With the ignition key in the ON position, use a multimeter to verify that the ECM is delivering a 5-volt reference to the sensor's supply pin.

4. 4

   Test the signal wire for continuity to the ECM and ensure it is not shorted to ground. Verify the ground circuit has low resistance.

1. 1

   Turn Off Power

   Turn the ignition key to the OFF position.

2. 2

   Repair Wiring

   If the diagnostic checks reveal a short to ground or a broken wire in the harness, repair the damaged section using an approved electrical repair connector or terminal.

3. 3

   Replace Sensor

   If the harness and 5-volt supply test perfectly, the sensor itself has failed internally. Clean the area around the sensor to prevent debris from entering the fuel system, relieve fuel system pressure, unthread and remove the faulty fuel rail pressure sensor, install the new OEM sensor and torque to the manufacturer's specifications, and reconnect the electrical harness.

4. 4

   Validate Repair

   Turn the keyswitch to the ON position and leave it there for 1 minute. This allows the ECM to run its continuous diagnostic. The active fault code should change to INACTIVE, and the amber Check Engine light should turn off.

5. 5

   Clear Codes

   Use a recommended CNH/Cummins electronic service tool to clear the inactive fault codes from the ECM's memory.