New Holland ENG 546 – Engine Control Module (ECM) / Engine Controller: Fuel Pressure Sensor Voltage is Too High

This code indicates that the Engine Control Module (ECM) has detected that the signal voltage from the fuel rail/delivery pressure sensor is out of range high. Because this is a 3-wire sensor (5V reference, ground, and signal), a "voltage too high" condition typically means the signal wire is shorted to a voltage source (like the 5V supply or 12V battery), there is an open circuit on the sensor ground wire, or the sensor itself has failed internally.

• T6 series (T6.120 - T6.175)
• T7 series (T7.170 - T7.270)
• T8 series (e.g., T8040)
• T9 series
• Magnum series
• CR series (CR8.90, CR9.90, CR10.90)
• CX series (CX8080, CX8090)
• Farmall 90N
• 105U
• TR270B track loaders

1. 1

   Inspect the fuel pressure sensor and the engine wiring harness for physical damage, chafing, or melted wires.

2. 2

   Disconnect the fuel pressure sensor. Check the pins on both the sensor and the harness connector for moisture, corrosion, pushed-back pins, or debris.

3. 3

   With the key ON and the sensor disconnected, use a multimeter to verify that the ECM is providing exactly 5 volts to the sensor supply pin and that there is a solid ground on the return pin.

4. 4

   Check the signal wire on the harness side. If it reads 5V or 12V while disconnected from the sensor, the signal wire is shorted to a voltage source in the harness.

5. 5

   If the 5V supply, ground, and signal wires all test normal, the fault is internal to the fuel pressure sensor.

1. 1

   Power Down

   Turn the keyswitch to the OFF position and allow the ECM to power down completely.

2. 2

   Access the Sensor

   Locate the fuel rail pressure sensor. On Cummins-based engines, it is often located on the bottom front corner of the integrated fuel system module (IFSM) or directly on the high-pressure fuel rail.

3. 3

   Remove the Sensor

   Disconnect the electrical connector. Thoroughly clean the area around the sensor to prevent dirt from entering the high-pressure fuel system. Use a wrench to unthread the faulty sensor from the fuel rail.

4. 4

   Install the New Sensor

   Thread the new OEM fuel pressure sensor into the rail. Torque it to the manufacturer's specific specification (do not over-tighten, as this can damage the rail threads or the sensor).

5. 5

   Reconnect

   Plug the electrical connector back into the sensor, ensuring the locking tab clicks into place.

6. 6

   Clear the Code

   Turn the keyswitch to the ON position and leave it there for 1 minute to allow the ECM to run its continuous diagnostic check. The fault code status should change to INACTIVE, and the amber Check Engine light should turn off. Start the engine and check for fuel leaks.