Case IH F-641-06 - ECU – Engine Control Unit (ECU): eVGT actuator over temperature error

The Electronic Variable Geometry Turbocharger (eVGT) actuator internal temperature exceeds its safe operating threshold (>125°C / 257°F). This overheating is most commonly caused by the actuator motor overworking due to soot/carbon buildup seizing the turbocharger vanes, or from excessive electrical resistance/voltage issues.

• MAGNUM AFS Connect
• Magnum 250
• Magnum 280
• Magnum 310
• Magnum 340
• Magnum 370
• Magnum 380
• Magnum Rowtrac
• Optum 300 CVT
• Steiger Series
• Quadtrac Series
• 240 Series Axial-Flow Combines

1. 1

   Verify Active Fault: Use the Case IH Electronic Service Tool (EST) to confirm the fault is currently active.

2. 2

   Mechanical Vane Test: Disconnect the actuator linkage from the turbocharger. Manually move the sector gear/unison ring on the turbo from stop to stop. If it does not make full, smooth travel, the turbo vanes are seized with carbon/soot, which is what caused the actuator to overheat.

3. 3

   Inspect for External Heat/Leaks: Check for exhaust leaks, missing heat shields, or coolant leaks from the actuator gasket that could be artificially heating the actuator housing.

4. 4

   Electrical Circuit Check: Inspect the wiring harness between the ECU and the eVGT actuator. Check for shorts to ground, high resistance, or damaged pins that could cause voltage irregularities.

1. 1

   Power Down

   Turn off the machine, allow the exhaust system to cool completely, and disconnect the battery.

2. 2

   Remove the Actuator

   Drain the coolant (if dealing with a liquid-cooled actuator housing) and unbolt the eVGT actuator from the turbocharger bearing housing.

3. 3

   Address Turbo Binding (If Applicable)

   If the diagnostic mechanical test revealed sticking vanes, the turbocharger must be cleaned of carbon deposits or replaced. Installing a new actuator on a bound turbo will cause the new actuator to fail immediately.

4. 4

   Install Replacement Actuator

   If the turbo sector gear moves freely, the fault is internal to the actuator's circuit board/motor. Mount the new eVGT actuator to the turbocharger.

5. 5

   Reconnect Harness

   Reconnect the CAN bus/power electrical harness to the actuator, ensuring connections are clean, tight, and free of corrosion.

6. 6

   Calibrate

   Reconnect the battery. Connect the Case IH EST and perform the mandatory eVGT actuator calibration/learn procedure so the ECU can map the new actuator's sweep limits.

7. 7

   Clear and Test

   Clear the F-641-06 fault code from the ECU and test run the engine under load to ensure the code does not return.