Massey Ferguson 520384.16 – Engine Control Unit (ECU): Air Mass Flow Sensor over temperature warning

The integrated temperature sensor within the Mass Air Flow (MAF) sensor detects an intake air temperature that exceeds the maximum safe threshold, or an internal short/failure in the sensor causes a false high-temperature reading.

• 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
• MF 7700 series
• MF IDEAL 8
• MF IDEAL 9

1. 1

   Visually inspect the air intake pipe, air filter housing, and hose clamps for cracks, looseness, or vacuum leaks that can alter airflow and temperature dynamics.

2. 2

   Verify that the engine air filter and pre-filter are not heavily clogged, as operating in extremely dusty conditions without proper pre-filtration can damage intake sensors.

3. 3

   Inspect the MAF sensor connector for water intrusion, corrosion, or damaged pins, which can cause a short in the wiring harness and lead to a falsely high temperature reading.

4. 4

   Use AGCO's Electronic Diagnostic Tool (EDT) to monitor live intake air temperature and mass air flow readings. If the temperature reads an impossible value (e.g., maxed out on a cold engine), the sensor is internally shorted.

1. 1

   Preparation

   Turn off the engine, remove the key, and disconnect the negative battery terminal to prevent electrical spikes.

2. 2

   Locate the Sensor

   Locate the MAF sensor, which is mounted on the main air intake pipe between the air filter housing and the engine intake manifold.

3. 3

   Disconnect Wiring

   Carefully press the release tab on the electrical connector and pull it away from the MAF sensor.

4. 4

   Remove the Sensor

   Depending on the specific intake design, either loosen the hose clamps securing the MAF sensor housing inline with the intake pipe, or remove the Torx/metric screws securing the sensor probe to the intake housing.

5. 5

   Clean the Area

   Wipe away any dust or debris from the intake pipe opening. Do not use harsh chemical cleaners inside the intake as they can damage the new sensor.

6. 6

   Install the New Sensor

   Insert the new MAF sensor. Ensure the airflow direction arrow on the sensor matches the direction of air traveling toward the engine.

7. 7

   Reassembly

   Tighten the mounting screws or hose clamps securely to prevent vacuum leaks. Reconnect the electrical harness until it clicks into place.

8. 8

   Clear Codes

   Reconnect the battery. Use the AGCO EDT or a compatible heavy-duty OBD scanner to clear the inactive 520384.16 fault code from the ECU.