New Holland ENG 265 – Engine Controller (Engine ECU / ECM): Fuel Temperature Sensor voltage is too low (or very low)

The engine controller has detected an abnormally low voltage signal from the fuel temperature sensor circuit (often specifically at pin A35 of the engine controller harness). This typically indicates a short to ground in the sensor wiring, a failed sensor, or a connector issue. When this code is active, the engine ECM will substitute a default value for the fuel temperature, which often results in a protective power derate (low power/poor performance) to prevent engine damage.

• T6
• T7
• T6000
• T7000
• TG255
• TG285
• TJ275
• TJ325
• CR9090
• CX8080
• CX8090
• E235BSR
• E265
• E305

1. 1

   Visually inspect the fuel temperature sensor (located on the fuel filter housing, fuel line, or primary fuel system manifold) and its connector for physical damage, corrosion, or moisture intrusion.

2. 2

   Trace the wiring harness from the sensor back to the Engine ECU. Look for chafed wires, melted insulation, or pinch points that could cause a short to ground.

3. 3

   Measure the voltage at the fuel temperature sensor signal pin (identified as pin A35 on the engine controller).

4. 4

   Perform a sensor disconnect test: Disconnect the fuel temperature sensor. If the diagnostic voltage reading immediately goes high (triggering code ENG 263), the sensor has failed internally. If the voltage remains low, there is a short to ground in the wiring harness or a fault within the Engine ECU.

1. 1

   Preparation

   Turn off the machine, remove the key, and disconnect the battery to prevent electrical spikes.

2. 2

   Access the Sensor

   Locate the fuel temperature sensor on the engine block water jacket or primary fuel system manifold lines.

3. 3

   Harness Repair (If Applicable)

   If the diagnostic checks revealed a short to ground in the wiring, repair the chafed/damaged section of the harness using proper weather-sealed splices, or replace the harness section.

4. 4

   Sensor Replacement (If Applicable)

   Disconnect the 2-pin sealed oval plug interface from the sensor. Using a wrench (often a 19mm spanner hex), unthread the faulty sensor from the fuel manifold. Have a rag ready to catch any minor fuel spillage. Thread the new OEM fuel temperature sensor into the port (M14 x 1.5 metric pitch threads are common) and tighten to OEM torque specifications. Reconnect the electrical harness, ensuring the weather seal clicks securely into place.

5. 5

   Clear Codes and Test

   Reconnect the battery. Use a diagnostic tool (such as the CNH Electronic Service Tool or Jaltest) to clear the inactive ENG 265 fault code from the Engine ECU. Start the engine and verify that the code does not return and that engine power is restored.