Massey Ferguson 10.X.26 – Air Conditioning Module (AIRCON): No Engine Coolant Temperature Information Received On The CAN BUS To AC Module (AIRCON)

The Air Conditioning control module is failing to receive the required engine coolant temperature data over the tractor's Controller Area Network (CAN BUS). The AC system relies on this data to regulate cab heating/cooling and to prevent the AC compressor from overloading an overheating engine.

• 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
• 5410
• 5420
• 5425
• 5430
• 5435
• 5440
• 5450

1. 1

   Check for Engine ECU Codes using an AGCO Electronic Diagnostic Tool (EDT) / FenDias for Engine Coolant Temperature Sensor faults. If the Engine ECU doesn't know the temperature, it cannot broadcast it.

2. 2

   Verify live data in the Engine ECU to ensure coolant temperature is reading accurately (e.g., not -40°C or 150°C).

3. 3

   Inspect the CAN BUS twisted-pair wiring between the Engine ECU and the AC Module for chafing, breaks, or short circuits.

4. 4

   Inspect the harness connectors at the AC Module (located in the cab roof or behind dash panels) for loose pins, moisture intrusion, or corrosion.

1. 1

   Disconnect Battery

   Always disconnect the negative battery terminal before repairing CAN wiring or replacing sensors to prevent electrical spikes.

2. 2

   Address Sensor Faults

   If diagnostics revealed a faulty Engine Coolant Temperature Sensor, locate the sensor on the engine block/thermostat housing. Unplug the connector, unscrew the old sensor, and install the replacement. Top off any lost engine coolant.

3. 3

   Repair CAN Wiring

   If the sensor is fine but the CAN signal is lost, trace the CAN lines from the AC module. Repair any broken wires using proper automotive-grade solder and heat shrink. Clean any corroded connector pins with electrical contact cleaner and apply dielectric grease.

4. 4

   Reassemble and Clear Codes

   Reconnect the battery. Turn the ignition ON and use the AGCO diagnostic tool to clear the 10.X.26 fault code from the AIRCON module.

5. 5

   Test the System

   Start the tractor and allow it to reach operating temperature. Turn on the AC and verify that the cab climate control functions normally and the fault code does not return.