Massey Ferguson E412.04 – Engine ECU: EGR Gas Temperature Sensor Low Voltage (ECU)

The engine controller is detecting that the voltage signal from the Exhaust Gas Recirculation (EGR) temperature sensor has dropped below the normal operating threshold, typically pointing to a short circuit to ground or an open circuit in the sensor or its wiring harness.

• 7616
• 5612
• 7622
• Interim Tier 4 (2012-2015)
• 7614
• 5611
• 7615
• 5610
• 5613
• 7620
• 5609
• 7618
• 5608
• 7619
• 7626
• 7624

1. 1

   Inspect the wiring harness running from the EGR Gas Temperature Sensor to the Engine ECU for melted wires, chafing against the engine block, or pinched lines

2. 2

   Disconnect the sensor and check the pins on both the sensor side and the harness side for corrosion, moisture, or pushed-back pins

3. 3

   Use a multimeter to check the reference voltage coming from the ECU to the sensor connector

4. 4

   Test the signal wire for continuity to the ECU and ensure it is not shorted to the chassis ground

5. 5

   Test the internal resistance of the sensor; an open circuit or a dead short indicates the sensor has failed internally

1. 1

   Power Down

   Turn off the tractor and disconnect the battery to prevent electrical spikes to the EEM4 controller.

2. 2

   Locate the Sensor

   Locate the EGR Gas Temperature Sensor, which is threaded into the EGR cooler or exhaust manifold piping.

3. 3

   Removal

   Disconnect the electrical pigtail. Apply penetrating oil to the threads and allow it to soak to prevent stripping the threads during removal. Carefully unthread the sensor.

4. 4

   Installation

   Apply a small amount of high-temp anti-seize to the threads of the new sensor (if not already pre-coated) and thread it into the EGR piping. Tighten to the manufacturer's torque specification.

5. 5

   Reconnection

   Reconnect the electrical harness, ensuring the locking tab clicks into place.

6. 6

   Clear Codes

   Reconnect the battery. Use an AGCO diagnostic tool (like WinEEM3/4) to clear the E412.04 fault code from the Engine ECU.

7. 7

   Test Run

   Start the engine and allow it to reach operating temperature to verify the EGR system is functioning dynamically and the code does not return.