Case IH F-518694-12 - ECU – Engine Control Unit (ECU): Exhaust flap actuator supply voltage out of range

The engine's control system has detected an internal electrical fault, a supply voltage anomaly, or a physical jam/sticking condition within the smart exhaust flap actuator.

• MAGNUM AFS Connect
• 240 Series Axial-Flow Combines (7240, 8240, 9240)
• Austoft 9000 Sugarcane Harvesters
• Austoft 9900 Sugarcane Harvesters
• Magnum Series
• Optum Series
• Vestrum Series

1. 1

   Inspect the exhaust flap actuator's power supply and ground wiring for shorts, broken wires, or high resistance in the harness connecting the actuator to the ECU.

2. 2

   Verify the CAN bus configuration and ensure the smart actuator is properly communicating with the network.

3. 3

   Use a diagnostic service tool to perform an active 'exhaust flap test' to check if the actuator is moving correctly or if it is physically binding.

4. 4

   Check the exhaust flap valve itself for heavy soot accumulation, increased friction, or sticking.

5. 5

   Verify that the machine does not have an underlying high battery voltage issue or an ECU over-temperature condition.

1. 1

   Power Down

   Turn off the machine, disconnect the battery, and allow the exhaust system to cool completely.

2. 2

   Inspect the Harness

   Locate the exhaust flap actuator (typically mounted on the exhaust piping downstream of the turbocharger). Disconnect the electrical connector and inspect the pins for corrosion, moisture, or damage.

3. 3

   Test the Circuit

   Using a multimeter, verify that the actuator is receiving the correct supply voltage from the ECU and that the CAN lines have proper continuity.

4. 4

   Check for Mechanical Binding

   If the wiring is intact, manually inspect the exhaust flap linkage (if accessible) to ensure the valve isn't seized by carbon buildup. Clean the valve if necessary.

5. 5

   Replace the Actuator

   If the wiring is good, the flap moves freely, and the FMI 12 failure persists at each ECU startup, the smart actuator has suffered an internal failure. Remove the mounting hardware and replace the exhaust flap actuator assembly.

6. 6

   Calibrate and Clear

   Reconnect the wiring harness, restore battery power, and use the dealer diagnostic tool to clear the fault codes. Run the automated exhaust flap test to verify the repair.