Massey Ferguson E174.04 – Engine Control Unit (ECU): Fuel Temperature Sensor Low Voltage

The voltage signal returning from the fuel temperature sensor to the controller is below the normal operating range. This typically points to a short circuit to ground in the sensor wiring, a failed sensor, or a loss of the 5V reference signal.

• 7616
• 5612
• 7622
• Interim Tier 4 (2012-2015)
• 7614
• 5611
• 7615
• 5610
• 5613
• 7620
• 5609
• 7618
• 5608
• 7619
• 7626
• 7624
• 4707
• 4708
• 4709
• 4710
• 7714
• 7715
• 7716
• 7718
• 7719
• 7720
• 7722
• 7724

1. 1

   Inspect the wiring harness and the connector at the fuel temperature sensor for chafing, bare wires, or corrosion that could cause a short to ground.

2. 2

   Disconnect the sensor and turn the key to the ON position. Check for a 5V DC reference voltage coming from the ECU to the sensor connector.

3. 3

   Measure the resistance across the sensor's pins. At 20°C (68°F), it should read approximately 2.5 kOhms (2402 - 2619 ohms). At 100°C, it should read around 0.186 kOhms. If the sensor reads open or shorted (0 ohms), it has failed internally.

1. 1

   Turn off the tractor, remove the key, and disconnect the negative battery cable to prevent electrical spikes.

2. 2

   Locate the fuel temperature sensor on the engine (check the main fuel filter housing assembly).

3. 3

   Depress the locking tab and disconnect the electrical pigtail from the sensor.

4. 4

   Clean the area around the sensor to prevent dirt from entering the fuel system.

5. 5

   Unthread the faulty sensor from the housing.

   Have a rag ready, as a small amount of fuel may leak.

6. 6

   Install the new sensor and torque to 25 Nm.

   Thread size is typically M12x1.5. Ensure the sealing ring is properly seated.

7. 7

   Reconnect the electrical harness until it clicks into place.

8. 8

   Reconnect the battery, turn the key on, and use an AGCO diagnostic service tool to clear the E174.04 / SPN 174 FMI 4 fault code from the ECU.

9. 9

   Start the engine and check for fuel leaks and ensure no check engine lights return.