Massey Ferguson 10.02.09 – AIRCON: Air Conditioning Evaporator Temperature Sensor Open Circuit

The climate control system has detected an 'open circuit' (a break in the electrical path or infinite resistance) on the circuit belonging to the AC evaporator temperature sensor. When this circuit is open, the system cannot read the evaporator temperature, which typically results in the AC compressor being disabled to protect the system.

• 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
• 4707
• 4708
• 4709
• 4710
• 5608
• 5609
• 5610
• 5611
• 5612
• 5613
• 7614
• 7615
• 7616
• 7618
• 7619
• 7620
• 7622
• 7624
• 7626
• 7714S
• 7719S

1. 1

   Visually inspect the evaporator temperature sensor (inside the cab roof HVAC unit), its wiring pigtail, and the main harness connector for unplugged connections, broken wires, or corrosion.

2. 2

   Unplug the sensor and measure its resistance across the two pins using a digital multimeter. A reading of 'OL' (Open Loop) or infinite resistance indicates internal failure.

3. 3

   If the sensor tests within normal resistance specifications, check the wiring harness for continuity between the sensor connector and the AIRCON module pins.

1. 1

   Access the HVAC Unit

   Gain access to the tractor's HVAC evaporator box (usually located in the cab roof; refer to the specific model's service manual for panel removal).

2. 2

   Locate the Sensor

   Find the evaporator temperature sensor probe, which is pushed directly into the fins of the evaporator core.

3. 3

   Disconnect

   Unplug the sensor's electrical connector from the cab wiring harness.

4. 4

   Remove

   Carefully pull the old sensor probe straight out of the evaporator fins.

5. 5

   Install

   Gently insert the new sensor probe into the exact same location in the evaporator core, ensuring you do not damage the delicate aluminum fins.

6. 6

   Reconnect & Reassemble

   Plug the new sensor into the wiring harness, reassemble the roof/HVAC panels, and clear the 10.02.09 fault code via the tractor's diagnostic menu.

7. 7

   Test

   Run the tractor and engage the AC to verify the compressor cycles properly and the code does not return.