Massey Ferguson 10.02.05 – AIRCON: Cab Temperature Sensor Open Circuit (AIRCON)

The system has detected an "open circuit" in the cab temperature sensor circuit. This means there is a break in the electrical path—either the sensor itself has failed internally (infinite resistance), a wire has been cut or broken, or a connector has come unplugged.

• 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
• MF7724S

1. 1

   Locate the cab temperature sensor (typically mounted in the cab headliner, pillar, or HVAC control panel area) and verify that it is securely plugged in.

2. 2

   Inspect the wiring harness running from the sensor to the AIRCON module. Look for pinched wires, chafing, or severed lines.

3. 3

   Disconnect the sensor and check the pins for corrosion, pushed-out pins, or moisture, which can interrupt the circuit.

4. 4

   Measure the resistance (Ohms) across the two terminals of the cab temperature sensor. If the multimeter reads 'OL' (Open Loop) or infinite resistance, the sensor has failed internally. If the sensor reads a normal resistance value, the open circuit is in the wiring harness or the module itself.

1. 1

   Power Down

   Turn off the tractor and disconnect the battery to prevent electrical shorts during repair.

2. 2

   Access the Sensor

   Remove the interior trim panels necessary to access the cab temperature sensor.

3. 3

   Repair Wiring (If Applicable)

   If the diagnostic checks revealed a broken wire, splice and heat-shrink the broken wire, or replace the damaged section of the harness.

4. 4

   Replace Sensor (If Applicable)

   If the sensor tested open, unclip the faulty sensor from its mounting bracket and install the new OEM replacement.

5. 5

   Reassembly

   Plug the electrical connector back into the sensor and reinstall any interior trim panels.

6. 6

   Clear Codes

   Reconnect the battery, turn the ignition on, and use a diagnostic tool to clear the 10.02.05 fault code. Test the A/C system to ensure the climate control is reading the cabin temperature accurately.