Case IH 19839 – Engine Control Module (ECM): Turbo charger actuator position sensor voltage is higher than expected

The Engine Control Module (ECM) has detected that the signal voltage returning from the Variable Geometry Turbocharger (VGT) actuator position sensor is exceeding the maximum normal operating threshold. This typically indicates a short circuit to a high-voltage source (like battery voltage), an open ground circuit in the sensor harness, or an internal failure of the actuator's position sensor.

• Tier 4b
• Case IH Magnum series tractors
• Case IH Steiger series tractors
• Case IH Axial-Flow Combines (e.g., 2388, 7120, and newer models with 8.3L, 8.9L, 9.0L, or 15L engines)
• Case IH Puma and Optum series tractors

1. 1

   Inspect the wiring harness between the ECM and the VGT actuator for chafing, melting, or pinched wires that could cause a short to voltage

2. 2

   Disconnect the VGT actuator and check the pins for corrosion, pushed-back pins, or moisture intrusion

3. 3

   Using a multimeter, probe the actuator harness connector to verify the 5V reference supply is correct (not shorted to 12V/24V) and test the ground pin for continuity to the chassis/ECM ground

4. 4

   Remove the actuator and manually move the sector gear/vanes on the turbocharger to check for mechanical binding or soot buildup

1. 1

   Disconnect Batteries

   Turn off the master disconnect or disconnect the negative battery cables.

2. 2

   Drain Coolant (if applicable)

   Some VGT actuators are water-cooled. If so, drain the engine coolant below the level of the turbocharger.

3. 3

   Remove the Actuator

   Disconnect the electrical harness and remove the mounting bolts securing the VGT actuator to the turbocharger housing.

4. 4

   Clean the Mating Surface

   Ensure the mounting surface on the turbo is clean and free of old gasket material.

5. 5

   Install the New Actuator

   Mount the new actuator using a new gasket (e.g., Bear the Sealer VGT gasket) and torque the bolts to OEM specifications. Reconnect the coolant lines (if applicable) and the electrical harness.

6. 6

   Refill Coolant

   Refill and bleed the cooling system.

7. 7

   Perform Calibration

   CRITICAL STEP. You must use the Case IH Electronic Service Tool (EST) or a compatible diagnostic scanner to perform the 'VGT Actuator Automatic Calibration Procedure.' The new actuator will not function correctly and will throw an 'Out of Calibration' code (like SPN 641 FMI 13) until it learns the physical end-stops of the turbocharger vanes.