Massey Ferguson 10.01.09 – AIRCON: Air Conditioning Evaporator Temperature Sensor Open Circuit

The control module has detected a break in the electrical circuit for the evaporator temperature sensor, or the sensor itself has failed internally, resulting in infinite resistance. When this fault is active, the system typically disables the A/C compressor to prevent the evaporator core from freezing over, meaning cab cooling will not be possible.

• 7724S
• 5712SL
• 7722
• 7722S
• 5713SL
• 7720S
• 7716
• 7718
• T4
• 7715
• 5710SL
• 7726
• 7726S
• 5711SL
• 7718S
• 7719
• 7714
• 7716S
• 7720
• Tier 4 (2015-2021)
• 7715S
• 7724
• 4700 Series
• 4707
• 4708
• 4709
• 4710
• 5600 Series
• 5608
• 5609
• 5610
• 5611
• 5612
• 5613
• 5700 SL Series
• 7600 Series
• 7614
• 7626
• 7700 Series
• 7700S Series
• 8600 Series

1. 1

   Connect the AGCO Electronic Diagnostic Tool (EDT) or a compatible PC scanner and check live data for the evaporator temperature sensor to see if it is reading an impossible value (e.g., extreme negative temperature).

2. 2

   Locate the evaporator temperature sensor on the HVAC unit (usually housed in the cab roof) and inspect the wiring harness and connector for physical damage, corrosion, or backed-out pins.

3. 3

   Disconnect the sensor and measure the resistance (ohms) across its terminals using a multimeter. If the multimeter reads 'OL' (open loop/infinite resistance), the sensor has failed internally.

4. 4

   If the sensor tests within normal resistance specifications, check for continuity in the wiring harness between the sensor connector and the AIRCON module to rule out a broken wire.

1. 1

   Turn off the tractor and disconnect the battery

   to prevent electrical shorts.

2. 2

   Access the HVAC unit.

   On most Massey Ferguson tractors, this requires removing the inner cab roof panel or accessing the unit under the seat, depending on the specific model.

3. 3

   Locate the evaporator temperature sensor

   inserted into the evaporator core housing.

4. 4

   Disconnect the electrical harness from the sensor.

5. 5

   Carefully pull or unclip the faulty sensor

   from the evaporator fins/housing.

6. 6

   Insert the new evaporator temperature sensor

   into the exact same location to ensure accurate temperature readings.

7. 7

   Reconnect the electrical harness.

8. 8

   Reassemble the cab panels.

9. 9

   Reconnect the battery, turn on the ignition, and use the diagnostic tool to clear the 10.01.09 fault code.

10. 10

    Start the tractor and engage the A/C

    to verify that the compressor engages and cooling is restored.