Case IH F-518695-14 - ECU – Engine Control Unit (ECU): Exhaust flap stuck during power up test

This code indicates that the smart exhaust flap actuator (which controls exhaust backpressure for emissions management, SCR temperature control, and engine braking) has reported a system failure over the CAN bus during the machine's initial key-on power-up self-test. The Engine Control Unit has detected that the flap is either physically jammed, experiencing excessive friction, or suffering from an internal electrical/CAN communication failure that prevents it from sweeping its full range of motion.

• MAGNUM AFS Connect
• 240 Series (7240, 8240, 9240)
• Austoft 9900
• Vestrum
• Optum
• Magnum
• Farmall

1. 1

   Inspect the exhaust flap actuator's wiring harness and connector for proper supply voltage, undervoltage, broken cables, or short circuits.

2. 2

   Verify CAN bus communication to ensure the CAN controller is functioning correctly and the actuator is communicating without timeout errors.

3. 3

   Check the physical exhaust flap valve inside the exhaust pipe for carbon buildup, rust, or mechanical binding that would prevent the actuator motor from moving it.

1. 1

   Cool Down

   Ensure the machine is turned off and the exhaust system has completely cooled down to prevent severe burns.

2. 2

   Locate the Actuator

   Locate the exhaust flap actuator mounted on the exhaust pipe/muffler assembly.

3. 3

   Disconnect and Inspect

   Unplug the electrical connector to the actuator. Inspect the pins for corrosion, moisture, or pushed-out terminals.

4. 4

   Isolate the Issue (Mechanical vs. Electrical)

   Unbolt the electronic actuator motor from the mechanical exhaust flap housing.

5. 5

   Test the Flap

   Manually actuate the mechanical flap by hand. It should move freely. If it is seized or binding, use a high-quality carbon penetrant/exhaust cleaner to free the valve. If the valve remains seized, the mechanical exhaust pipe section containing the flap must be replaced.

6. 6

   Replace the Actuator

   If the mechanical flap moves freely but the fault code persists during a key cycle, the smart actuator has failed internally. Install a new exhaust flap actuator.

7. 7

   Reassemble and Clear

   Bolt the new actuator into place, reconnect the wiring harness, and cycle the ignition key. The ECU will perform a new power-up test; if successful, the code will move to an inactive state and can be cleared.