Case IH 3831 – Engine ECU: Intake Valve Position Signal Too Low

The Engine Control Unit (ECU) is detecting that the physical source (SRC) voltage or signal returning from the valve position sensor, which monitors the Throttle Valve Actuator, has dropped below the acceptable threshold. This typically indicates a short to ground in the sensor circuit, a damaged wiring harness, or a physical failure of the sensor inside the actuator.

• Farmall
• skid steer
• SV300
• SR175
• Farmall 95U Pro EP
• Farmall 105U Pro EP
• Farmall 115U Pro EP
• Puma
• Steiger
• Maxxum

1. 1

   Inspect the wiring harness and connectors between the Engine ECU and the Throttle Valve Actuator for chafing, corrosion, or pushed-out pins.

2. 2

   Use a multimeter to check the signal wire from the Throttle Valve Actuator to the ECU for a short to ground.

3. 3

   Verify that the ECU is sending the correct reference voltage to the actuator.

4. 4

   Ensure the throttle valve itself is not mechanically stuck or jammed by carbon buildup, preventing the sensor from reading the correct physical position.

1. 1

   Disconnect battery

   Turn off the machine, remove the key, and disconnect the negative battery cable to prevent electrical shorts.

2. 2

   Locate and disconnect actuator

   Locate the Throttle Valve Actuator (TVA) on the engine's intake manifold and disconnect the electrical connector.

3. 3

   Remove faulty actuator

   Remove the mounting bolts securing the TVA to the intake manifold and remove the faulty actuator.

4. 4

   Clean mating surface

   Clean the mating surface on the intake manifold to ensure a proper seal.

5. 5

   Install new actuator

   Install the new Throttle Valve Actuator and torque the mounting bolts to OEM specifications.

6. 6

   Reconnect electrical and battery

   Reconnect the electrical connector, ensuring it clicks securely into place, then reconnect the battery.

7. 7

   Initialize and clear codes

   Cycle the key to the ON position to allow the ECU to recognize the new actuator. Use a diagnostic tool to clear the inactive 3831 fault code from the Engine ECU.