Massey Ferguson 4360.1 – Engine ECU (AGCO SISU POWER Engine Electronic Control Module / EEM4): Issue With The DOC Inlet Temperature Sensor (ECU) / SCR Catalyst Inlet Temperature Value Not Plausible

The Failure Mode Identifier (FMI) 10 indicates a "Rationality Error" or an "Abnormal Rate of Change." This means the engine control unit is receiving a signal from the Diesel Oxidation Catalyst (DOC) or Selective Catalytic Reduction (SCR) inlet temperature sensor, but the temperature value is not plausible compared to other exhaust sensors, or it is fluctuating at a rate that is physically impossible for exhaust gas.

• 4710
• 7724S
• 5712SL
• 7722S
• 7722
• 5713SL
• 7720S
• 7716
• 7718
• T4
• 7715
• 5710SL
• 7726
• 4708
• 7726S
• 4707
• 4709
• 5711SL
• 7718S
• 7719
• 7714
• 7716S
• T4 (2015-2021)
• 7720
• Tier 4 (2015-2021)
• 7715S
• 7724
• 5608
• 5609
• 5610
• 5611
• 5612
• 5613
• 6612
• 6613
• 6614
• 6615
• 6616
• 6712
• 6713
• 7614
• 7615
• 7616
• 7618
• 7619
• 7620
• 7622
• 7624
• 7626
• 7714 through 7726
• 8650
• 8660
• 8670
• 8680
• 8690
• 8727 through 8740
• 9540
• 9560
• IDEAL series

1. 1

   Check for multiple active codes: If other faults are active (especially voltage high/low codes like FMI 3 or FMI 4), troubleshoot those first.

2. 2

   Perform a cold soak temperature comparison: Turn the ignition ON (engine OFF) after the tractor has been sitting overnight. Monitor the DOC inlet, DOC outlet, and DPF outlet temperature sensors. All should read within 25°C (45°F) of ambient temperature. Significant deviation indicates a faulty DOC inlet sensor.

3. 3

   Inspect harness and pins: Check the electrical connections upstream of the ECU. Inspect the sensor harness connector and ECU pins for corrosion, spread pins, or pushed-out wires.

4. 4

   Perform a wiggle test: While monitoring the sensor voltage on a diagnostic tool, wiggle the wire harness from the aftertreatment device to the ECU. A large deviation in voltage indicates an intermittent short or open circuit in the wiring.

1. 1

   Preparation

   Shut off the engine, apply the parking brake, chock the wheels, and disconnect the batteries. Ensure the exhaust system has completely cooled to avoid severe burns.

2. 2

   Locate the Sensor

   Locate the DOC inlet temperature sensor. It is positioned in the exhaust pipe stream, as close as possible to the inlet of the Diesel Oxidation Catalyst (DOC).

3. 3

   Disconnect Wiring

   Slide back any protective heat sleeving and disconnect the electrical harness from the sensor.

4. 4

   Remove the Sensor

   Depending on the specific exhaust configuration, remove the retaining clip or use a wrench to unscrew the sensor from the exhaust pipe bung.

5. 5

   Install the New Sensor

   Apply a small amount of anti-seize compound to the threads of the new sensor (if not already pre-applied by the manufacturer) and thread it into the exhaust pipe. Tighten to OEM torque specifications.

6. 6

   Reconnect

   Reconnect the electrical harness and ensure the locking tab clicks into place. Re-secure any protective heat shielding.

7. 7

   Clear Codes

   Reconnect the batteries. Turn the key ON and use a diagnostic tool to clear the inactive fault codes.

8. 8

   Verification

   Start the engine and let it idle. Monitor the DOC inlet temperature via the diagnostic tool to ensure it rises smoothly and plausibly as the exhaust heats up.