Massey Ferguson 8 – Automatic Air Conditioning Module: External Air Temperature Sensor Fault - Sensor short-circuited

The system has detected that the voltage or resistance signal from the outside ambient temperature sensor is out of bounds (shorted). As a direct consequence of this fault, the automatic climate control is disabled, and the water valve opening and air conditioning are forced into manual control mode.

• 7724S
• Interim Tier 4 (2012-2015)
• 7722S
• 7722
• 7615
• 7720S
• 7716
• 7718
• 7726
• 7715
• 7616
• 7618
• 7619
• 7626
• 7624
• 7726S
• 7614
• 7718S
• 7620
• 7719
• 7714
• 7716S
• 7622
• 7720
• Tier 4 (2015-2021)
• 7715S
• 7724
• MF 8600 Series (e.g., 8670, 8690)
• MF 8400 Series (e.g., 8450, 8460, 8470, 8480)
• MF 7600 Series
• MF 6700 S Series
• MF 5600 / 6600 Series
• Various Dyna-4, Dyna-6, and Dyna-VT equipped models with auto air-con

1. 1

   Locate the outside temperature sensor (connector X358) outside the cab, typically mounted under the A/C condenser or near the front grille/cab suspension harness junction.

2. 2

   Disconnect the X358 sensor connector and use a multimeter to measure the resistance across the sensor's pins. If resistance reads zero or near zero, the sensor is internally shorted.

3. 3

   If the sensor shows normal resistance, trace the wiring harness between the X358 connector and the Automatic Air Conditioning Module. Look for chafed wires causing a short to ground or a short between the two signal wires.

1. 1

   Turn off the tractor and disconnect the battery to ensure safety while working on the electrical system.

   Ensure safety while working on the electrical system.

2. 2

   Locate the external air temperature sensor (X358) outside the cab.

   Locate the sensor outside the cab.

3. 3

   Unplug the electrical connector from the sensor.

   Disconnect the sensor.

4. 4

   If your diagnostic checks proved the sensor is faulty, unclip or unscrew the old sensor from its mounting bracket.

   Remove the faulty sensor.

5. 5

   Install the new sensor into the mounting location.

   Mount the replacement sensor.

6. 6

   Reconnect the electrical harness connector until it clicks securely.

   Ensure a secure connection.

7. 7

   Reconnect the battery and turn on the tractor.

   Restore power to the machine.

8. 8

   Test the automatic climate control system to ensure it regulates temperature properly and verify that the fault code has cleared from the instrument panel.

   Verify the repair was successful.