Case IH 518685-01 - ACM – ACM: Internal failure in the hitch settings selector knob

The physical encoder dial/knob on the armrest used to navigate and adjust the rear hitch settings has suffered an internal hardware or logic failure, preventing it from sending the correct position or selection data to the control system.

• MAGNUM AFS Connect
• Case IH Magnum AFS Connect Series 180
• Case IH Magnum AFS Connect Series 200
• Case IH Magnum AFS Connect Series 220
• Case IH Magnum AFS Connect Series 240
• Case IH Magnum AFS Connect Series 250
• Case IH Magnum AFS Connect Series 280
• Case IH Magnum AFS Connect Series 310
• Case IH Magnum AFS Connect Series 340
• Case IH Magnum AFS Connect Series 380
• Case IH Magnum AFS Connect Series 400
• Case IH Steiger / Quadtrac AFS Connect Series

1. 1

   Check the AFS Pro 1200 display for related fault codes (e.g., 518685-00, 518685-06, 518685-13, 518686-02) that might indicate a wiring issue rather than an internal knob failure.

2. 2

   Physically inspect the turn-and-press encoder dial on the Multicontroller armrest for physical damage, sticking, or liquid intrusion.

3. 3

   Verify ACM communication to ensure there are no broader network issues (e.g., fault code 1012 indicates a total loss of communication with the ACM).

4. 4

   Verify the Armrest Control Module (ACM) software version using the Electronic Service Tool (EST), as software updates (e.g., ACM software version 1.1.0.0 or 1.2.0.0) are sometimes required for AFS Connect armrest modules.

1. 1

   Power Down

   Turn off the tractor and disconnect the battery to prevent electrical shorts while working on the armrest.

2. 2

   Disassemble the Armrest

   Remove the upper trim panels of the Multicontroller armrest to access the internal control stalks and switch modules.

3. 3

   Disconnect the Module

   Locate the hitch settings selector knob/encoder assembly. Disconnect the wiring harness connecting it to the main Armrest Control Module (ACM).

4. 4

   Replace the Component

   Remove the mounting screws securing the failed encoder knob/switch assembly and install the OEM replacement part.

5. 5

   Reassemble and Power Up

   Reconnect the wiring harness, reassemble the armrest trim, and reconnect the battery.

6. 6

   Clear Codes and Calibrate

   Turn the key on, clear the inactive fault codes via the AFS Pro 1200 display or EST, and test the turn-and-press dial to ensure hitch settings can be navigated successfully.