New Holland NH 3102 – Engine ECU (Engine Controller / EDC7): Fuel pressure monitoring CP3 - ALL OTHER FAULTS / Rail Pressure Sensor CP3 - Signal Below Range Min

The high-pressure fuel injection pump (Bosch CP3) is not delivering adequate fuel pressure to the common rail, or there is excessive fuel leakage within the high-pressure system preventing the rail from reaching the minimum required pressure.

• New Holland T4 Series (T4.65 to T4.115)
• New Holland T5 Series (T5.85 to T5.115)
• New Holland T6 Series
• New Holland T7 Series (T7.220 to T7.270)
• New Holland T8.xxx Series

1. 1

   Check the low-pressure fuel supply for restrictions, most commonly caused by a clogged fuel filter.

2. 2

   Connect the New Holland Atlas diagnostic software and monitor the CP3 Pulse Width Modulation (PWM) output.

3. 3

   Evaluate the PWM readings: minimum should be 3% at engine idle and maximum 24% at full load. Readings above 24% indicate the pump is overworking to compensate for excessive fuel leakage.

4. 4

   If PWM is above 24%, isolate the leak by removing the fuel return lines from the fuel rail overpressure valve and the injector/transfer tubes to physically check for excessive return flow.

1. 1

   Replace Fuel Filters

   Start by replacing the primary and secondary fuel filters to eliminate a simple low-pressure restriction. Prime the fuel system.

2. 2

   Test the Pressure Relief Valve

   If the Atlas diagnostic tool shows a PWM above 24%, remove the return line from the fuel rail pressure relief valve. Crank or run the engine. If a significant amount of fuel is passing through the relief valve, the valve has failed open and must be replaced.

3. 3

   Test the Injectors

   If the relief valve is not leaking, remove the return lines from the injectors/transfer tubes. Identify any injector with excessive return flow and replace it.

4. 4

   Replace the CP3 Pump

   If there are no leaks found in the rail or injectors, the fuel supply to the pump is good, but the CP3 output remains low (or the pump has failed internally), the Bosch CP3 high-pressure injection pump must be replaced.

5. 5

   Clear and Verify

   After replacing the faulty component(s), use the diagnostic tool to clear code NH 3102. Run the machine under load to verify that the rail pressure meets the commanded parameters and the code does not return.