Case IH 3828 – Engine Control Unit (ECU): ECU Power stages : Throttle valve actuator power stage: Open load

The Engine Control Unit (ECU) has detected an "open load" (an open electrical circuit) on the power stage circuit that drives the Throttle Valve Actuator (TVA). An open load indicates that the electrical path is broken—this is typically caused by a disconnected harness plug, a severed wire, or an internal break in the actuator's electromagnetic coil.

• Case IH Farmall Series (95U, 105U, 115U Pro EP)
• Case IH Magnum Series
• Case IH Steiger Series
• Case IH Skid Steer Loaders (SV300)

1. 1

   Visually inspect the wiring harness and electrical connector at the Throttle Valve Actuator for disconnected plugs, backed-out pins, or severe corrosion.

2. 2

   Perform a harness continuity test by disconnecting the harness from both the TVA and the ECU. Use a digital multimeter to check for continuity on the power and ground circuits between the ECU pins and the TVA connector. Infinite resistance indicates a break in the wiring harness.

3. 3

   Test the actuator coil by measuring the internal resistance of the Throttle Valve Actuator solenoid/coil across its terminals. If the multimeter reads 'OL' (Open Loop) or infinite resistance, the actuator has failed internally.

1. 1

   Power Down

   Turn off the machine and disconnect the negative battery cable to prevent electrical shorts during the repair.

2. 2

   Locate the TVA

   Locate the Throttle Valve Actuator on the engine's air intake system.

3. 3

   Disconnect Wiring

   Depress the locking tab and disconnect the electrical harness connector from the TVA.

4. 4

   Address Wiring (If Applicable)

   If diagnostics pointed to a wiring issue, splice and repair the broken wire or replace the damaged connector terminal.

5. 5

   Remove the Faulty Actuator

   If the TVA itself is internally open, remove the mounting bolts securing the valve body to the intake manifold.

6. 6

   Install the New Part

   Clean the mating surface on the intake manifold. Install the new Throttle Valve Actuator with a new gasket/seal (if applicable) and torque the mounting bolts to OEM specifications.

7. 7

   Reassembly

   Reconnect the electrical harness plug to the new actuator.

8. 8

   Clear Codes

   Reconnect the battery. Use a diagnostic scan tool to clear the inactive 3828 fault code from the ECU memory.

9. 9

   Test Run

   Start the engine and verify that the throttle responds correctly and the fault code does not return.