Massey Ferguson 4363.03 – Engine ECU: Issue With The SCR Outlet Temperature Sensor (ECU)

SCR catalyst outlet gas temperature sensor voltage is above normal or there is an open circuit. The sensor is reporting a voltage signal to the controller that exceeds the maximum expected threshold, which typically happens when the sensor's internal wiring breaks (open circuit) or the signal wire is shorted to a high voltage source (like the battery).

• 4710
• 7724S
• 5712SL
• Interim Tier 4 (2012-2015)
• 7722
• 7722S
• 7615
• 5613
• 5713SL
• 7720S
• 7716
• 7718
• T4
• 7715
• 5710SL
• 7726
• 7616
• 7618
• 5608
• 4708
• 7619
• 7626
• 7726S
• 7624
• 4707
• 4709
• 5711SL
• 7614
• 7718S
• 5610
• 7620
• 7719
• 7714
• 7716S
• T4 (2015-2021)
• 5612
• 7622
• 7720
• Tier 4 (2015-2021)
• 5611
• 7715S
• 5609
• 7724

1. 1

   Check for primary CAN communication codes (e.g., U1611/U1612) or module supply voltage codes. Troubleshoot these first, as a lack of module voltage will cause sensor faults.

2. 2

   Visually inspect the SCR Outlet Temperature Sensor for a loose mounting, physical tampering, or the sensor being open to the atmosphere.

3. 3

   Disconnect the sensor and inspect the pins for corrosion, moisture, or pushed-back terminals.

4. 4

   Use a multimeter to check the wiring harness between the sensor connector and the Engine ECU. Test for continuity to rule out a broken wire or open circuit, and test for a short to battery voltage.

1. 1

   Preparation

   Turn off the tractor, remove the key, and disconnect the battery to prevent electrical spikes. Allow the exhaust system to cool completely, as the SCR catalyst operates at extremely high temperatures.

2. 2

   Locate the Sensor

   Locate the SCR Outlet Temperature Sensor. It is threaded into the exhaust pipe immediately downstream of the SCR catalyst assembly.

3. 3

   Removal

   Disconnect the electrical harness connector from the sensor. Use a suitable wrench or specialized sensor socket to carefully unthread the sensor from the exhaust pipe. (Penetrating oil may be required if the sensor is seized from exhaust heat).

4. 4

   Installation

   Apply a small amount of high-temp anti-seize to the threads of the new sensor (ensure no anti-seize gets on the sensor probe itself). Thread the new sensor into the exhaust outlet and tighten to the manufacturer's specified torque.

5. 5

   Reconnection

   Reconnect the sensor's electrical connector, ensuring it clicks securely into place. Reconnect the tractor's battery.

6. 6

   Clear Codes & Verify

   Connect a diagnostic service tool (such as the AGCO WinEEM4 Service Tool) to the machine. Clear the 004363.03 / SPN 4363 FMI 3 fault code. Start the engine and monitor the live data for the SCR outlet temperature to ensure it is reading plausibly and the code does not return.