Massey Ferguson 001639.18 – ECM: Engine Fan Speed Below Normal Range

The Engine Control Module (ECM) has detected that the engine cooling fan is operating at a significantly lower speed than commanded. This discrepancy indicates an abnormal or missing signal from the fan speed sensor, which can cause the Vistronic fan to run continuously, not engage, or operate erratically, potentially leading to engine overheating or reduced performance.

• 3000 Series
• 5400 Series
• 6200 Series
• 6400 Series
• 7400 Series
• 8200 Series
• 8700 Series
• 8S Series

1. 1

   Check the radiator for debris and verify the coolant level is correct to ensure airflow is not restricted

2. 2

   Inspect the fan drive belt for wear, looseness, or slipping

3. 3

   With the engine off, manually rotate the fan to check the mechanical clutch; it should turn smoothly with some resistance. Look for fluid leaks

4. 4

   Inspect the wiring harness and electrical connectors leading to the fan clutch solenoid and speed sensor for corrosion, chafed wires, or loose pins

5. 5

   Test the solenoid electrically by checking for 12V power and measuring resistance (BorgWarner units should draw 1.0 to 2.0 Amps when 12V is applied)

6. 6

   Test the fan speed sensor by back-probing the connector with a multimeter while manually rotating the fan to verify a voltage signal is generated

1. 1

   Perform initial mechanical checks

   Clean the radiator and replace the fan drive belt if it is worn or slipping.

2. 2

   Repair wiring and connectors

   Repair or replace any damaged wiring or corroded connectors found during inspection to resolve intermittent connections.

3. 3

   Test solenoid fail-safe

   Unplug the fan clutch solenoid. The fan should default to full speed. If it engages at full speed when unplugged but not otherwise, the issue is likely in the control circuit or solenoid.

4. 4

   Replace fan speed solenoid

   If the solenoid fails electrical testing (incorrect resistance or no response to voltage), replace the fan speed solenoid valve.

5. 5

   Replace fan clutch assembly

   If the fan speed sensor is faulty or the clutch has mechanically failed (rough rotation, seized, or leaking), replace the entire Vistronic fan clutch assembly.

6. 6

   Verify repair

   Clear the fault codes, run the tractor to operating temperature, and verify that the fan engages and disengages correctly without triggering code 001639.18.