Massey Ferguson 3562.31 – Engine Control Unit (ECU): Boost Pressure Sensor Signal Issue (ECU)

The engine control system is receiving an erratic, missing, or out-of-range electrical signal from the intake boost pressure sensor. In the J1939 standard, an FMI 31 often indicates a condition that exists but cannot be strictly classified by other failure modes (such as a signal plausibility issue or an unexpected pressure drop during cranking).

• 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
• 7614
• 7615
• 7616
• 7618
• 7619
• 7620
• 7622
• 7624
• 7626

1. 1

   Inspect the wiring harness leading to the boost pressure sensor for chafing, melting, or breaks.

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 verify that the sensor is receiving the correct 5V reference voltage and ground from the ECU.

4. 4

   Inspect the intake manifold, turbocharger piping, and intercooler boots for physical leaks, cracks, or loose clamps. A massive boost leak can cause the ECU to flag a signal plausibility issue because the measured pressure does not match the commanded pressure.

1. 1

   Preparation

   Turn off the tractor, remove the key from the ignition, and allow the engine to cool.

2. 2

   Locate the Sensor

   Locate the boost pressure sensor, which is mounted directly on the engine's intake manifold.

3. 3

   Disconnect

   Carefully depress the locking tab on the electrical connector and pull it away from the sensor.

4. 4

   Removal

   Unbolt or unthread the faulty boost pressure sensor from the intake manifold.

5. 5

   Installation

   Clean the mating surface on the manifold. Install the new OEM boost pressure sensor and tighten it to the manufacturer's specified torque (do not overtighten, as the manifold or sensor housing can crack).

6. 6

   Reconnection

   Plug the electrical connector back in until it clicks securely.

7. 7

   Clear Codes

   Connect a diagnostic scan tool to the tractor's diagnostic port, clear the 003562.31 fault code from the ECU, and run the engine to verify that the code does not return.