Massey Ferguson 1 – AIRCON: Air Conditioning Vent Temperature Sensor Open Circuit

The control module has detected an open circuit in the sensor that measures the temperature of the air coming out of the HVAC vents. An "open circuit" typically indicates infinite resistance, which is caused by a broken wire, a disconnected plug, or a completely failed internal sensor element.

• 7724S
• Interim Tier 4 (2012-2015)
• 7722
• 7722S
• 7615
• 7720S
• 7716
• 7718
• 7726
• 7715
• 7616
• 7618
• 7619
• 7626
• 7726S
• 7624
• 7614
• 7718S
• 7620
• 7719
• 7714
• 7716S
• 7622
• 7720
• Tier 4 (2015-2021)
• 7715S
• 7724
• 4707
• 4708
• 4709
• 4710
• 5608
• 5609
• 5610
• 5611
• 5612
• 5613
• 5710SL
• 5711SL
• 5712SL
• 5713SL

1. 1

   Inspect the wiring harness and connectors between the AIRCON module and the Vent Temperature Sensor for chafed wires, corrosion, or disconnected pins.

2. 2

   Disconnect the sensor and use a multimeter to measure its resistance. If the multimeter reads 'OL' (Open Loop) or infinite resistance, the sensor has failed internally.

3. 3

   Check the harness side of the connector for the proper reference voltage and ground coming from the AIRCON module to rule out a broken wire in the main harness.

1. 1

   Turn off the tractor and ensure the HVAC system is powered down.

2. 2

   Locate the Air Conditioning Vent Temperature Sensor.

   Typically mounted directly into the HVAC ducting or evaporator housing behind the dash or in the cab roof, depending on the specific tractor cab layout.

3. 3

   Carefully disconnect the electrical connector from the sensor.

4. 4

   Remove the faulty sensor from the air vent/duct.

5. 5

   Install the new replacement sensor into the ducting.

6. 6

   Reconnect the electrical connector.

7. 7

   Use a compatible diagnostic tool to clear the 10.00.01 fault code from the AIRCON module.

   Such as Massey Ferguson EDT or Jaltest.

8. 8

   Run the tractor and test the A/C system to ensure proper vent temperature readings are being registered by the module.