New Holland ENG 3819 – Engine Control Unit (EDC / ECU): Throttle Valve Actuator (TVA) Circuit - Over Current Error For H-Bridge

The H-bridge is the internal driver circuit within the engine controller that operates the DC motor for the Throttle Valve Actuator (TVA). An over-current error indicates that the actuator motor is drawing excessive electrical current, which is typically caused by a short circuit in the wiring, an internally shorted actuator motor, or a mechanically stuck throttle valve flap forcing the motor to work too hard.

• L220
• L230
• L316
• L318
• L320
• C238
• SR175
• B90B
• B100B

1. 1

   Inspect the wiring harness between the EDC (60-pin connector, pins A34 and A49) and the Throttle Valve Actuator for chafing, melted insulation, or short circuits.

2. 2

   Check the TVA and EDC connectors for corrosion, moisture, or pushed-out pins.

3. 3

   Remove the intake tubing and inspect the throttle valve flap for mechanical binding caused by carbon or soot buildup.

4. 4

   Test the internal resistance of the TVA motor to check for an internal electrical short.

5. 5

   Verify the EDC condition; if wiring and TVA are normal, the internal H-bridge power stage may be permanently damaged.

1. 1

   Disconnect the battery

   Disconnect the machine's battery to prevent electrical sparks or further module damage.

2. 2

   Remove the intake tube

   Remove the intake tube connected to the Throttle Valve Actuator.

3. 3

   Disconnect electrical connectors

   Disconnect the electrical connector to the TVA and the nearby air pressure/temperature sensor.

4. 4

   Remove mounting hardware

   Remove the bolts and nuts securing the TVA to the manifold.

5. 5

   Remove the old TVA

   Remove the old TVA and clean the mating surface.

6. 6

   Install the new TVA

   Install the new Throttle Valve Actuator and torque the mounting bolts/nuts to 20 - 30 N·m (15 - 22 lb ft).

7. 7

   Reconnect electrical connections

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

8. 8

   Reinstall the intake tube

   Reinstall the intake tube and tighten the clamps.

9. 9

   Clear fault codes

   Reconnect the battery, turn the key on, and use the appropriate New Holland service tool to clear the fault codes and reset any self-learning parameters if required.