Massey Ferguson 1639.19 – Engine Control Unit (ECU): Fan speed request CAN signal missing

The ECU has lost the CAN signal to or from the fan's internal speed controller, meaning it can no longer regulate the fan clutch.

• 7616
• 5612
• 7622
• Interim Tier 4 (2012-2015)
• 7614
• 5611
• 7615
• 5610
• 5613
• 7620
• 5609
• 7618
• 5608
• 7619
• 7626
• 7624
• 8650
• 8660
• 8670
• 8680
• 8690
• 5S Series
• 6S Series
• 8S Series

1. 1

   Turn the ignition off for a minimum of 60 seconds, then turn it back on to see if the CAN communication resets and the code clears.

2. 2

   Verify battery voltage, as the EEM4 system is highly sensitive to voltage drops and related codes (like SPN 168 FMI 1) often trigger alongside CAN communication faults.

3. 3

   Inspect the cooling unit harness and the specific electrical connector at the Vistronic fan clutch for backed-out pins, corrosion, or wire chafing.

4. 4

   Using a multimeter, check the resistance and voltage on the CAN High and CAN Low wires at the fan connector to ensure the network is intact between the fan and the Engine ECU.

1. 1

   Disconnect Power

   Disconnect the tractor's battery to prevent electrical shorts and ensure safety.

2. 2

   Access the Fan

   Remove the engine side panels and the fan shroud hardware to gain access to the cooling package.

3. 3

   Disconnect Wiring

   Unplug the electrical harness connector directly at the Vistronic fan clutch.

4. 4

   Remove the Drive Belt

   Relieve tension on the engine accessory drive belt and slip it off the fan pulley.

5. 5

   Remove the Fan Assembly

   Unbolt the fan clutch assembly from the engine water pump or mounting hub.

6. 6

   Swap the Blades

   If the replacement part is just the clutch drive, unbolt the plastic fan blades from the old clutch and transfer them to the new Vistronic clutch. (Note: Ensure the blades are not cracked or damaged).

7. 7

   Reinstallation

   Mount the new fan assembly to the hub, route and tension the drive belt, and reconnect the electrical harness.

8. 8

   Clear Codes

   Reconnect the battery. Use the WinEEM4s service tool (or equivalent dealer diagnostic tool) to clear the logged 001639.19 / SPN 1639 fault code and test run the tractor to verify the fan engages properly.