Massey Ferguson 412.03 – Engine Control Unit (ECU): EGR Gas Temperature Sensor High Voltage

The controller is receiving a voltage signal from the Exhaust Gas Recirculation (EGR) temperature sensor that exceeds the maximum expected threshold, typically indicating an open circuit or a short to a power source.

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

1. 1

   Inspect the EGR temperature sensor and its wiring harness for physical damage, chafing against hot exhaust components, or melted wires.

2. 2

   Disconnect the sensor and check the pins for corrosion, moisture, or pushed-out terminals.

3. 3

   Turn the key to the ON position (engine off) and use a multimeter to measure the voltage at the sensor connector. Verify that the 5V reference and ground are present. If the signal wire reads a full 5V or 12V with the sensor unplugged, there is a short to power in the harness.

4. 4

   Measure the resistance (Ohms) across the sensor's terminals. If the multimeter reads 'OL' (Open Loop) or infinite resistance, the sensor has failed internally and must be replaced.

1. 1

   Power Down

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

2. 2

   Locate the Sensor

   Locate the EGR Gas Temperature Sensor, which is threaded into the EGR cooler or exhaust gas recirculation piping on the engine block.

3. 3

   Removal

   Disconnect the electrical pigtail from the sensor. Spray the threads with penetrating oil and allow it to soak. Carefully remove the sensor using a properly sized wrench or O2 sensor socket to avoid stripping the threads.

4. 4

   Installation

   Apply a small amount of anti-seize compound to the threads of the new sensor (if not pre-applied by the manufacturer), being careful not to get any on the sensor probe. Thread it in by hand, then tighten to OEM torque specifications.

5. 5

   Reconnection

   Reconnect the electrical harness, ensuring the locking tab clicks into place. Secure the wire away from hot exhaust components.

6. 6

   Clear Codes

   Reconnect the battery, turn the key on, and use a diagnostic scan tool to clear the 000412.03 code. Start the engine and verify the code does not return.