New Holland NH 3103 – Engine Control Module (ECM) / Engine Controller: Fuel pressure signal - ABOVE NORMAL

The fuel pressure signal from the rail pressure sensor indicates that the fuel pressure has exceeded the maximum limit for the given engine rating, or the sensor's signal voltage is reading too high.

• T4
• T5
• T6
• T7
• MXM/TM
• Magnum
• B100C
• B110C
• B115C (Stage IV)
• CR8.90
• CR9.90
• 9090L

1. 1

   Check CP3 pump PWM output using a diagnostic tool (should be a minimum of 3% at engine idle and a maximum of 24% at full load)

2. 2

   Check for fuel leakage from the overpressure (pressure relief) valve in the fuel rail or from the injector/transfer tubes if the PWM output is above 24%

3. 3

   Inspect fuel supply for low pressure, which is often caused by a fuel filter restriction

4. 4

   Test the fuel rail pressure sensor and its wiring harness for a short circuit to a high voltage source

1. 1

   Filter Maintenance

   Inspect and replace the primary and secondary fuel filters if there is any sign of restriction or contamination.

2. 2

   Wiring Inspection

   Inspect the wiring harness connecting the ECM to the fuel rail pressure sensor. Repair any chafed wires or short circuits.

3. 3

   Leak Down Test

   Disconnect the fuel return lines from the pressure relief valve on the fuel rail. If fuel is leaking heavily from the valve during operation, the valve is faulty and must be replaced.

4. 4

   Sensor Replacement

   If the wiring is intact, the filters are clean, and there are no mechanical leaks at the relief valve, the fuel rail pressure sensor itself has likely failed internally (biased high) and should be replaced.

5. 5

   Clear Codes

   After replacing the faulty component, clear the fault codes from the ECM and test run the machine under load to verify the CP3 PWM output returns to normal parameters (3% to 24%).