Massey Ferguson 1639.18 – Engine Control Unit (ECU): Engine Cooling Vistronic Fan Speed Solenoid Issue

The Vistronic fan is an electronically controlled viscous fan drive. The control module monitors the fan's rotational speed and adjusts the internal proportional solenoid valve to engage or disengage the viscous fluid based on engine, transmission, and hydraulic temperatures. This code triggers when the controller detects that the fan is rotating at a lower speed than commanded, indicating either a mechanical failure of the fan clutch, a failed internal solenoid, or an electrical communication/wiring issue.

• 7616
• 5612
• 7622
• Interim Tier 4 (2012-2015)
• 7614
• 5611
• 7615
• 5610
• 5613
• 7620
• 5609
• 7618
• 5608
• 7619
• 7626
• 7624
• 7714 through 7726S
• 6465
• 6475
• 6480
• 6485
• 6490
• 7485
• 7490
• 7495
• 4700 Series
• 5600 Series
• 5700 Series
• 6700 Series

1. 1

   Wiring Harness Inspection: Check the wiring loom that runs down to the hub on the front of the Vistronic fan for rubbing against the Vistronic unit or pulleys, causing it to chafe and short out.

2. 2

   Connector Check: Inspect the electrical connector at the fan clutch to ensure it is securely plugged in, clean, and free of corrosion or pushed-out pins.

3. 3

   Physical Fan Inspection: With the engine off, check the fan blade assembly for physical damage or excessive play in the bearing. The fan should have some viscous drag when turned by hand but should not be completely seized or completely freewheeling.

4. 4

   Drive Belt Inspection: Verify the fan/water pump drive belt is properly tensioned and not slipping.

1. 1

   Disconnect Power

   Disconnect the tractor's battery to prevent electrical shorts during the repair.

2. 2

   Address Wiring (If Applicable)

   If the diagnostic check revealed a chafed wiring harness, repair the damaged wires or replace the fan wiring loom section. Route the new harness carefully and secure it with zip ties to prevent future rubbing. If the harness is intact, the Vistronic fan clutch itself has failed and must be replaced.

3. 3

   Clear the Area

   Remove the fan cowl/shroud retaining bolts and push the cowl back over the fan to gain clearance.

4. 4

   Remove the Belt

   Relieve tension on the serpentine/fan drive belt and remove the belt from the fan pulley.

5. 5

   Disconnect the Fan

   Unplug the electrical connector for the Vistronic fan solenoid.

6. 6

   Remove the Clutch

   Unbolt the Vistronic fan clutch assembly from the mounting hub/water pump.

7. 7

   Transfer Blades

   Unbolt and transfer the plastic fan blades to the new Vistronic fan clutch (if the new part does not include blades).

8. 8

   Install New Part

   Install the new fan clutch assembly onto the hub and torque the mounting bolts to OEM specifications.

9. 9

   Reassembly

   Reconnect the electrical connector (ensuring safe routing), reinstall the drive belt, and secure the fan cowl.

10. 10

    Clear Codes

    Reconnect the battery, start the engine, and use an AGCO Electronic Diagnostic Tool (EDT) to clear the 001639.18 fault code. Run the tractor to operating temperature to verify the fan engages properly.