Massey Ferguson E1639.18 – ECU (Engine Control Unit) / EEM4 controller: Engine Cooling Vistronic Fan Speed Solenoid Issue

The Vistronic fan is an electronically controlled viscous fan clutch used to regulate engine cooling. This code triggers when the control module detects that the fan's rotational speed is moderately lower than requested, or the speed signal is missing entirely. This typically points to a failing fan speed sensor, a defective proportional solenoid inside the clutch, or a wiring harness issue.

• 7616
• 5612
• 7622
• Interim Tier 4 (2012-2015)
• 7614
• 5611
• 7615
• 5610
• 5613
• 7620
• 5609
• 7618
• 5608
• 7619
• 7626
• 7624
• 7600 Series
• 6400 Series
• 6485
• 6490
• 6495
• 7400 Series
• 7495
• 6S
• 8S
• 7700 Series

1. 1

   Inspect the wiring harness and connector pins between the Vistronic fan and the ECU for chafed wires, corrosion, or a loose connection

2. 2

   Verify that the fan speed request CAN signal is being properly transmitted from the ECU

3. 3

   Check the fan speed sensor output for an open circuit or short circuit to ground/battery

4. 4

   Inspect the Vistronic fan clutch for physical damage, excessive play, or leaks of the internal viscous silicone fluid

1. 1

   Disconnect Power

   Disconnect the tractor's battery to prevent accidental shorts or ECU damage.

2. 2

   Disconnect Electricals

   Unplug the electrical harness connector from the Vistronic fan clutch.

3. 3

   Clear Access

   Depending on the specific model (e.g., 7600 series), remove the fan cowl/shroud and the fan/alternator drive belts to gain clear access to the cooling package.

4. 4

   Remove the Fan Assembly

   Unbolt the fan blade assembly from the Vistronic clutch hub.

5. 5

   Remove the Clutch

   Unbolt and remove the Vistronic fan clutch from the water pump or engine support hub.

6. 6

   Install New Parts

   Mount the new Vistronic fan clutch to the hub and reattach the fan blades to the new clutch.

7. 7

   Reassembly

   Reinstall the drive belts, ensuring proper tension, and refit the fan cowl.

8. 8

   Reconnect

   Plug the electrical harness back into the fan clutch and reconnect the battery.

9. 9

   Clear Codes

   Use an AGCO Electronic Diagnostic Tool (EDT) to clear the E1639.18 fault code and run the engine to verify proper fan speed modulation.