Massey Ferguson 10.00.05 – AIRCON: Cab Temperature Sensor Open Circuit (AIRCON)

The controller is detecting infinite resistance or a complete loss of signal on the circuit dedicated to the interior cab temperature sensor. This is typically caused by a broken wire, an unplugged connector, or a sensor that has failed internally (open circuit).

• 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
• 5700 series
• 6700 series
• 7600 series
• 7700 series
• 8600 series
• 8S series
• 9695 rotary combine
• 9795 rotary combine
• WR9900 series windrowers

1. 1

   Perform a visual inspection of the cab temperature sensor (typically mounted in the headliner, near recirculation vents, or on the top right side of the fuse panel). Check the pigtail and connector for unplugged connections, backed-out pins, or corrosion.

2. 2

   Perform a sensor resistance test by disconnecting the sensor and measuring resistance across its terminals. If the multimeter reads 'OL' (Open Loop) or infinite resistance, the sensor has failed internally.

3. 3

   Perform a harness continuity test if the sensor tests good. Check the wiring harness between the sensor connector and the AIRCON module for chafed, pinched, or broken wires on both the signal and ground circuits.

4. 4

   Perform a voltage check by turning the key to the ON position and checking for a reference voltage (usually 5V) at the sensor connector to ensure the AIRCON module is sending the signal.

1. 1

   Power Down

   Turn off the machine and disconnect the battery ground cable to prevent electrical shorts during repair.

2. 2

   Access the Sensor

   Remove the necessary interior cab trim panels or fuse panel covers to access the cab temperature sensor.

3. 3

   Remove the Faulty Sensor

   Unplug the electrical connector. Unclip or unscrew the sensor from its mounting bracket.

4. 4

   Install the New Sensor

   Snap the new sensor into place and reconnect the wiring harness. Ensure the connector clicks and locks securely.

5. 5

   Reassemble

   Reinstall any interior trim panels or covers that were removed.

6. 6

   Clear Codes

   Reconnect the battery. Turn the ignition on and operate the HVAC system. Use the AGCO Electronic Diagnostic Tool (EDT) to clear the stored 10.00.05 fault code, or allow the system to run a self-check to see if the code moves from 'Active' to 'Inactive'.