Case IH 3831 – Engine ECU (EDC): Throttle Valve Actuator: DFC for valve position sensor physical SRC low / Intake valve position Signal Too Low

A low voltage or short-to-ground condition in the intake/throttle valve position sensor circuit, indicating the engine control module is receiving a voltage signal from the Throttle Valve Actuator (TVA) position sensor that falls below the minimum acceptable threshold.

• skid steer
• Farmall 115U Pro EP
• SR175
• Skid Steer Loaders (SSL)
• Compact Track Loaders (CTL)

1. 1

   Visually inspect the wiring harness leading to the Throttle Valve Actuator (TVA) for chafing, melting, or physical damage that could cause a short to ground.

2. 2

   Disconnect the TVA harness connector and the Engine ECU connector to check for pushed-back pins, corrosion, or moisture intrusion.

3. 3

   Using a multimeter, check the signal wire between the TVA position sensor and the Engine ECU for continuity to ground (a short to ground will pull the signal voltage low).

4. 4

   Remove the intake piping and physically inspect the throttle/intake valve flap to ensure it is not jammed by carbon buildup or debris.

1. 1

   Disconnect Power

   Turn off the machine and disconnect the negative battery terminal to prevent electrical spikes during repair.

2. 2

   Repair Wiring

   If the diagnostic checks revealed a short to ground in the harness, repair the damaged section of the wire, apply heat-shrink tubing, and re-loom the harness away from hot or vibrating engine components.

3. 3

   Replace the Actuator

   If the wiring tests perfectly, the internal position sensor of the Throttle Valve Actuator has failed. Remove the charge-air/intake hoses connected to the TVA, unbolt the TVA assembly from the intake manifold, clean the mating surface, install the new Throttle Valve Actuator with a new gasket/O-ring, and torque the mounting bolts to OEM specifications.

4. 4

   Reassemble and Clear Codes

   Reconnect the electrical harness and the battery. Use an electronic service tool (EST) or diagnostic scanner to clear the inactive 3831 fault code from the Engine ECU.

5. 5

   Test Run

   Start the engine and verify that the code does not return and that the engine operates without derate.