Case IH 518866-06 - BCM – BCM: ATC floor vent door actuator - over temperature

The system has detected an over-temperature condition associated with the Automatic Temperature Control (ATC) floor vent door actuator. This typically occurs when the actuator motor is physically jammed, binding, or internally shorted, causing it to draw excessive current and overheat.

• MAGNUM AFS Connect
• Magnum AFS Connect series
• Steiger AFS Connect series
• Optum models with advanced ATC
• Puma models with advanced ATC

1. 1

   Check for Physical Binding: Access the HVAC distribution box and manually inspect the floor vent door. Look for dust buildup, debris, or mechanical binding that would cause the actuator motor to stall and overheat.

2. 2

   Inspect Wiring: Check the LIN bus wiring harness and connector at the floor vent actuator for melted pins, corrosion, or a short to power/ground.

3. 3

   Actuator Test: If the door moves freely by hand but the code persists when the system tries to actuate the door, the actuator itself has likely failed internally.

1. 1

2. 2

   Power Down

   Turn off the machine and disconnect battery power to prevent electrical spikes.

3. 3

   Access the Actuator

   Remove the necessary cab trim panels to access the HVAC unit and locate the floor vent door actuator.

4. 4

   Remove the Faulty Actuator

   Disconnect the LIN electrical connector from the actuator. Remove the mounting screws and pull the actuator off the blend door shaft.

5. 5

   Install the New Actuator

   Seat the new actuator onto the door shaft, secure it with the mounting screws, and plug in the electrical connector.

6. 6

   Assign the LIN Address

   Connect the Case IH Electronic Service Tool (EST) to the tractor's diagnostic port. Navigate to the ATC/BCM module programming section. Run the procedure to reorganize the actuators. The EST will assign the correct LIN address to the newly installed floor vent actuator. This is a critical step, as the ATC/BCM cannot communicate with an unaddressed actuator.

7. 7

   Clear and Test

   Clear the 518866-06 fault code using the EST. Turn on the HVAC system and cycle the temperature/vent controls to verify the floor vent door opens and closes smoothly without logging a new code.