Massey Ferguson 10.00.26 – AC Module (AIRCON): No Engine Coolant Temperature Information Received On The CAN BUS To AC Module (AIRCON)

The Air Conditioning (AC) system relies on engine coolant temperature data to regulate cab climate and to prevent the AC compressor from overloading the engine during high-temperature conditions. This code indicates that the AC Module is failing to receive this specific data packet over the CAN BUS network from the Engine Control Unit (ECU).

• 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

1. 1

   Check for concurrent CAN BUS codes (e.g., 10.00.24 or 10.00.25) to determine if the entire CAN BUS connection to the AC module is compromised

2. 2

   Verify Engine ECU data using a diagnostic scan tool to check if the Engine ECU is successfully reading the Engine Coolant Temperature

3. 3

   Inspect CAN BUS wiring (CAN High and CAN Low) between the Engine ECU and the AC Module for continuity, shorts to ground, or shorts to power

4. 4

   Inspect connectors at both the AC Module (behind the cab control panel) and the Engine ECU for corrosion, backed-out pins, or moisture ingress

1. 1

   Disconnect battery

   Disconnect the battery before performing any electrical repairs.

2. 2

   Address Sensor Issues

   If the Engine ECU is not reading the coolant temperature, locate the Engine Coolant Temperature (ECT) sensor on the engine block or thermostat housing. Inspect its pigtail connector. Replace the ECT sensor or repair the sensor wiring harness if damaged.

3. 3

   Clean and Reseat Connectors

   If the ECT sensor is functioning but the AC module is not receiving the data, locate the CAN BUS harness connecting the cab modules to the engine modules. Disconnect the AC Module and Engine ECU connectors, clean the contacts using electrical contact cleaner, and securely reseat them.

4. 4

   Repair CAN BUS Wiring

   Repair any broken or chafed CAN BUS wires found during the diagnostic continuity test. Ensure the twisted-pair wiring structure is maintained if splicing is required.

5. 5

   Test and Clear Codes

   Reconnect the battery, clear the fault codes using a diagnostic tool, and run the tractor to verify if the code returns.

6. 6

   Module Replacement

   If the wiring is perfect, the Engine ECU is transmitting the data, and the code persists, the AC Module itself has an internal CAN transceiver failure and will require a software reflash or physical replacement.