Case IH 3864 – Engine Control Unit (ECU): EVGT electrical failure (internal failure)

Indicates that the internal electrical circuitry or motor of the turbocharger's electronic actuator has failed or is experiencing a critical internal fault, preventing it from properly adjusting the turbocharger vanes.

• Magnum Series (250, 280, 310, 340, 380, 400)
• Steiger / Quadtrac Series (350, 425, 475, 525, 555, 595, 645)
• Optum Series (270, 300 CVX)
• Puma Series

1. 1

   Inspect the dedicated EVGT actuator fuse (e.g., F-203, 20A Mini Yellow fuse on Optum/Magnum models)

2. 2

   Disconnect the vehicle engine harness from the ECU and check wiring between the EVGT actuator relay and actuator connector for continuity and shorts to ground

3. 3

   Turn the key switch to the ON position and check for a proper ground signal to the EVGT actuator

4. 4

   Inspect the turbocharger for mechanical binding (stuck vanes due to soot buildup or rust) which can overwork the actuator motor

1. 1

   Power Down

   Turn the ignition switch OFF and disconnect the battery to prevent electrical spikes.

2. 2

   Wiring Repair

   If the diagnostic checks revealed a short to ground in the harness (e.g., between the relay pin and actuator connector pin), repair or replace the affected wiring harness section.

3. 3

   Actuator / Turbocharger Replacement

   Remove the intake and exhaust piping connected to the turbocharger. Disconnect the coolant and oil feed/return lines. Unbolt and remove the failed EVGT actuator or the entire turbocharger assembly. Install the new turbocharger/actuator assembly and torque mounting bolts to OEM specifications. Reconnect all fluid lines and electrical connectors.

4. 4

   Calibration

   Connect the CNH Electronic Service Tool (EASY tool). Clear the fault memory in the ECU and, if a new actuator was installed, perform the EVGT learn/initialization procedure so the ECU can map the new actuator's sweep limits.