New Holland ENG 268 – Engine Control Module (ECM): Fuel Pressure in pump is not changing with operating conditions.

The Engine Control Module (ECM) monitors fuel pressure and expects it to fluctuate in response to changes in engine load and speed. This fault is triggered when the ECM detects that the fuel pressure signal remains constant despite the engine being loaded. When this occurs, the ECM will estimate fuel pressure, and engine power is typically reduced (derated).

• TM175
• T9 Series
• Magnum series
• CR9090
• CX8080
• CX8090
• FX30
• FX40

1. 1

   Check for associated active fault codes (such as 451, 452, 328, or 329) which indicate over-pumping or fuel inlet restriction

2. 2

   Inspect the suction side of the fuel system for air leaks, aeration, or excessive restrictions like a plugged fuel filter

3. 3

   Turn keyswitch OFF and inspect the fuel pressure sensor and connector pins for dirt, moisture, corrosion, or damage

4. 4

   Verify the ECM +5 VDC supply, signal, and return circuits to the fuel pressure sensor are intact and not shorted

5. 5

   Inspect the fuel pressure sensor circuit for signs of tampering if the fault is not repeatable or has many inactive counts

1. 1

   Turn Keyswitch OFF

   Ensure the machine is off before disconnecting any electrical components.

2. 2

   Service the Fuel Filters

   If the fuel filters have not been changed recently, replace them and bleed the fuel system to rule out a restriction or air in the lines.

3. 3

   Repair Wiring

   If connector pins are damaged or corroded, clean them or splice in a new electrical repair connector pigtail.

4. 4

   Replace the Fuel Pressure Sensor

   If the wiring and +5V supply are verified as good but the ECM still sees a constant pressure reading, replace the fuel pressure sensor.

5. 5

   Evaluate the Injection Pump

   If replacing the sensor does not resolve the issue and the fault is accompanied by active pump failure codes (e.g., 328, 329), the fuel injection pump (CAPS accumulator module) may have failed internally and will require replacement.

6. 6

   Clear Codes

   Reconnect all components, turn the keyswitch to the "ON" position, and use an electronic service tool to erase the inactive fault codes. Start the engine and let it idle to verify the fault does not return.