Case IH 19027 – Engine Control Unit (ECU) or Aftertreatment Control Module (ACM): Exhaust flap actuator supply voltage out of range

This code indicates an electrical fault where the control module detects that the voltage supplied to the electronic exhaust flap actuator (often part of the exhaust brake or thermal management system for SCR/DEF) is outside of the expected operating parameters. This typically points to a wiring issue (short circuit, open circuit) or an internal failure of the actuator motor itself.

• Tier 4b
• 240 Series Axial-Flow Combines
• Vestrum Series (Vestrum 100, 110, 120, 130)
• Puma Series
• Farmall models with CVT transmissions

1. 1

   Inspect the wiring harness between the ECU and the exhaust flap actuator for chafing, open circuits, or shorts to ground/power.

2. 2

   Disconnect the exhaust flap actuator and check the pins for corrosion, moisture intrusion, or bent terminals.

3. 3

   Use a multimeter to verify that the ECU is sending the correct supply voltage to the actuator connector when the key is in the ON position.

4. 4

   Check if the exhaust flap is physically jammed, which can cause the motor to burn out.

1. 1

   Turn off the machine, engage the parking brake, and disconnect the battery

   This prevents electrical spikes.

2. 2

   Locate the exhaust flap actuator

   It is mounted on the exhaust brake valve assembly in the exhaust stream.

3. 3

   Disconnect the electrical connector from the actuator.

4. 4

   Repair the harness or replace the pigtail connector.

   Perform this if the diagnostic checks revealed damaged wiring.

5. 5

   Unbolt the faulty exhaust flap actuator from the exhaust valve assembly.

   Perform this if the wiring and supply voltage are good, indicating the actuator motor has failed internally.

6. 6

   Install the new exhaust flap actuator and torque the mounting hardware to OEM specifications.

7. 7

   Reconnect the electrical harness and the battery.

8. 8

   Clear the fault codes using a diagnostic tool.

   Cycle the key to the ON position to allow the ECU to perform a power-up test on the new actuator to ensure it sweeps without sticking.