New Holland ENG 3831 – Engine Control Unit (ECU): Throttle Valve Actuator: DFC for valve position sensor physical SRC low

This code indicates that the voltage signal from the Throttle Valve Actuator (TVA) position sensor has dropped below the minimum acceptable threshold. This usually points to a "Short to Ground" (SRC low) condition within the sensor's physical circuit, meaning the controller is not receiving a plausible position signal from the throttle valve.

• F5C (DOC) Tier 3 and Tier 4A engines
• L218
• L220
• L223
• L225
• L230
• C232
• C238
• CR9090
• CX8080 Elevation
• CX8090 Elevation

1. 1

   Connect the Electronic Service Tool to verify if ENG 3831 is currently active. Clear the code, operate the machine, and see if it returns

2. 2

   Inspect the engine wiring harness and connectors for physical damage, chafing, or corrosion

3. 3

   Test the TVA position sensor circuit for a short to ground, paying special attention to the 60-pin engine ECU connector (specifically pins A34 and A49)

4. 4

   Verify that the ECU power stages supplying the throttle valve actuator are delivering the correct voltage and are not shorted

1. 1

   Clear and Retest

   Use the diagnostic tool to clear all fault codes. Start the engine and operate the machine. If ENG 3831 does not return, the issue may have been a temporary glitch. If it returns, proceed to step 2.

2. 2

   Repair Wiring

   If the multimeter tests in your diagnostic phase revealed a short to ground in the wiring harness between the ECU and the TVA, repair or replace the affected wiring section.

3. 3

   Access the TVA

   If the wiring and connectors test good, the Throttle Valve Actuator itself has likely failed internally. Disconnect the electrical connections to the TVA and the air pressure/temperature sensor.

4. 4

   Remove the Actuator

   Remove the intake tube and unbolt the Throttle Valve Actuator from the assembly.

5. 5

   Install the New Part

   Install the replacement Throttle Valve Actuator and reattach the intake tube. Torque the mounting bolts and nuts to the OEM specification of 20 - 30 N·m (15 - 22 lb ft).

6. 6

   Reconnect and Clear

   Reconnect the electrical harness to the TVA. Turn the key on, use the Electronic Service Tool to clear the fault codes, and run the engine to verify the repair.