Massey Ferguson E174.03 – Engine ECU: Fuel Temperature Sensor Voltage Above Normal or Open Circuit

The Engine Control Unit is receiving a signal from the fuel temperature sensor that is higher than the normal operating range, typically indicating an open circuit in the sensor's wiring harness or an internal sensor failure. Symptoms include a stored fault, warning lamp activation, reduced engine power (Degradation Level 1), and disabled fuel temperature dependent functions.

• 7616
• 5612
• 7622
• Interim Tier 4 (2012-2015)
• 7614
• 5611
• 7615
• 5610
• 5613
• 7620
• 5609
• 7618
• 5608
• 7619
• 7626
• 7624
• 4600 series
• 4608
• 4609
• 4610
• 4700 series
• 4707
• 4708
• 4709
• 4710
• 5400 series
• 5460
• 5475
• 5600 series
• 6400 series
• 6600 series
• 6700 series
• 7400 series
• 7600 series
• 7700 series
• 8700 series
• 9520
• 9530
• 9540
• 9560
• 9790
• Activia series
• Beta series

1. 1

   Locate the fuel temperature sensor on the main fuel filter housing

2. 2

   Disconnect the sensor and visually inspect the wiring harness and connector pins for corrosion, broken wires, or pushed-out pins (which cause an open circuit)

3. 3

   With the key ON, check the connector for a 5V DC reference voltage supplied by the ECU

4. 4

   Measure the resistance across the sensor pins. Nominal resistance should be approximately 2.5 kΩ at 20ºC (68ºF) and drop to 0.186 kΩ at 100ºC (212ºF). If the sensor reads completely open (infinite resistance), it is defective

1. 1

   Turn off the engine

   Turn off the engine and remove the key from the ignition.

2. 2

   Clean the area

   Clean the area around the main fuel filter housing to prevent dirt from entering the fuel system.

3. 3

   Disconnect the electrical pigtail

   Disconnect the electrical pigtail from the fuel temperature sensor.

4. 4

   Unscrew the faulty sensor

   Using a wrench, carefully unscrew the faulty sensor from the filter housing. Have a rag ready, as a small amount of fuel may leak out.

5. 5

   Install the new sensor

   Install the new sensor and tighten it to the manufacturer's specified torque (do not overtighten the brass threads).

6. 6

   Reconnect the electrical harness

   Reconnect the electrical harness, ensuring it clicks securely into place.

7. 7

   Clear the fault code

   Turn the key to the ON position and use a diagnostic service tool (like WinEEM3/4) to clear the stored E174.03 / SPN 174 FMI 3 fault code. Alternatively, run the engine to see if the active fault clears itself and full power is restored.