Massey Ferguson AC07 – Automatic Air-Conditioning (AIRCON) module: Outside temperature sensor Sensor open

The control module is detecting infinite resistance or a lack of continuity in the circuit for the ambient air temperature sensor (X358), typically caused by a disconnected plug, a broken wire in the harness, or an internal failure within the sensor itself.

• 7616
• 5612
• 7622
• Interim Tier 4 (2012-2015)
• 7614
• 5611
• 7615
• 5610
• 5613
• 7620
• 5609
• 7618
• 5608
• 7619
• 7626
• 7624
• 4700 Series
• 4707
• 4708
• 4709
• 4710
• 5400 Series
• 5600 Series
• 5700SL Series
• 6600 Series
• 7600 Series
• 7700 Series
• 7714
• 7726S
• 8600 Series
• 8670
• 8690
• 8700 Series

1. 1

   Locate the outside temperature sensor (X358) and visually check the electrical connector to ensure it is fully seated and not disconnected.

2. 2

   Unplug the sensor and inspect the pins for severe corrosion, moisture ingress, or pushed-out terminals, which can cause an open circuit reading.

3. 3

   Trace the wiring harness from the X358 sensor back toward the cab junction, looking for chafed, pinched, or severed wires.

4. 4

   Using a digital multimeter, measure the resistance across the two pins of the temperature sensor. If the multimeter reads 'OL' (Open Loop) or infinite resistance, the sensor has failed internally.

1. 1

   Power Down

   Turn off the tractor ignition and disconnect the negative battery cable to prevent electrical spikes.

2. 2

   Locate and Remove

   Locate the X358 outside temperature sensor. Depress the locking tab on the oval 2-pin electrical connector and pull it free from the sensor.

3. 3

   Dismount

   Unclip or unbolt the faulty sensor from its mounting bracket (many of these are press-fit or snap-in designs).

4. 4

   Install

   Press the new ambient temperature sensor into the mounting location until secure.

5. 5

   Reconnect

   Plug the electrical connector back into the sensor, ensuring the locking tab clicks into place.

6. 6

   Test

   Reconnect the battery and turn the ignition key to the ON position. Check the instrument panel to verify that the AC07 fault code has moved from 'Active' to 'Stored/Inactive' or has cleared entirely. Test the air conditioning system to ensure it is regulating cab temperature properly.