Case IH 3826 – Engine Control Unit (ECU): Throttle Valve Actuator (TVA) Circuit - Temperature dependent over-current error for H-bridge (power stage)

The Throttle Valve Actuator is an electronically controlled valve that regulates air flow into the intake manifold. This code triggers when the Engine Control Unit detects that the TVA motor is drawing excessive electrical current relative to its operating temperature. This is typically caused by a physically binding/stuck throttle valve blade, a failing internal actuator motor, or a short circuit in the wiring harness.

• skid steer
• Farmall 95U
• Farmall 105U
• Farmall 115U Pro EP
• MAXXUM 135
• MAXXUM 145
• MAXXUM 150
• Luxxum
• Quantum
• Steiger series
• SV250
• SV300
• SR220
• SR250
• TR
• TV380

1. 1

   Check the electrical connector at the Throttle Valve Actuator and the air pressure/temperature sensor to ensure pins are fully seated, clean, and free of corrosion.

2. 2

   Inspect the wiring harness between the ECU and the TVA for chafing, pinched wires, or exposed copper that could cause shorts to ground or battery.

3. 3

   Remove the intake tube connected to the TVA and inspect the throttle blade for heavy carbon/soot buildup or physical debris that might be jamming the valve.

4. 4

   If the wiring is intact and the valve blade moves freely (or is permanently seized internally), suspect a failure of the TVA's internal H-bridge circuit or motor.

1. 1

   Turn off the machine, remove the key, and disconnect the battery.

2. 2

   Disconnect the electrical connections to the Throttle Valve Actuator (TVA) and the nearby air pressure/temperature sensor.

3. 3

   Loosen the clamps/hardware and remove the intake tube connected to the TVA.

4. 4

   Remove the mounting bolts holding the TVA to the intake manifold.

5. 5

   Remove the faulty TVA and clean the mating surface on the manifold.

6. 6

   Install the new Throttle Valve Actuator and a new gasket.

7. 7

   Torque the TVA mounting bolts to 20 - 30 N·m (15 - 22 lb ft).

8. 8

   Reinstall the intake tube and torque its bolts/nuts to 20 - 30 N·m (15 - 22 lb ft).

9. 9

   Reconnect the electrical connections to the TVA and sensors.

10. 10

    Reconnect the battery.

    Note: You may need to use an electronic service tool (EST) to clear the fault code and restore the ECU's self-learning parameters for the new actuator.