New Holland ENG 3835 – Engine Control Unit (ECU): Throttle Valve Actuator - ECU Power stages: Throttle valve actuator power stage: SRC low.

The engine control unit is monitoring the electrical signal of the Throttle Valve Actuator (TVA) position sensor, and the signal circuit voltage has dropped below 0.0 V (Signal Range Check - Low). This condition typically points to a short circuit to ground, faulty wiring, or an internal failure of the TVA sensor itself. When this code is active, the machine may experience a crank-no-start condition or severe power loss because the valve may be closing off air to the engine.

• C232
• C238
• L218
• L220
• SV300
• SR175
• SV185

1. 1

   Verify the Code: Ensure the fault code is still present and in an active state.

2. 2

   Inspect the Wiring Harness: Check the wire harness between the ECU and the TVA (specifically looking at the 60-pin ECU connector pins A34/A49 and the TVA connector X-016). Look for chafing, melted wires, or a short to ground.

3. 3

   Inspect the Connectors: Ensure all connections are secure, tight, and free of corrosion, abrasion, or bent pins.

4. 4

   Mechanical Inspection: Remove the intake hose and physically inspect the Throttle Valve Actuator for a sticking, carbon-fouled, or jammed butterfly valve.

1. 1

   Disconnect battery

   Disconnect the machine's battery to prevent electrical shorts.

2. 2

   Disconnect electrical connections

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

3. 3

   Disconnect hose

   Disconnect the hose that runs from the TVA to the boost pressure modulator valve.

4. 4

   Remove intake tube

   Remove the intake tube connected to the TVA.

5. 5

   Remove mounting bolts

   Remove the mounting bolts (typically M6 x 64) and nuts securing the TVA to the intake manifold.

6. 6

   Remove faulty TVA

   Remove the faulty TVA and clean the mating surfaces.

7. 7

   Install new TVA

   Install the new Throttle Valve Actuator and the intake tube.

8. 8

   Install mounting bolts

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

9. 9

   Reconnect hose

   Reconnect the hose to the boost pressure modulator valve.

10. 10

    Reconnect electrical harnesses

    Reconnect the electrical harnesses to the TVA and the air pressure/temperature sensor.

11. 11

    Reconnect battery and clear codes

    Reconnect the battery, turn the ignition on, and clear the fault codes using a diagnostic tool (or verify the code changes from active to inactive).