Case IH 518685-00 - ACM – ACM: Hitch settings selector knob internal failure

The '-00' failure mode indicator generally points to a severe internal hardware fault, implausible signal, or complete loss of communication from the rotary encoder that controls the rear hitch settings.

• MAGNUM AFS Connect
• Magnum AFS Connect Series (Models 180, 200, 220, 240, 250, 280, 310, 340, 380, 400)
• Steiger AFS Connect Series
• Puma Series (Models 190, 200, 205, 215, 225, 230)

1. 1

   Inspect the physical hitch settings selector knob on the armrest for physical damage, sticking, or lack of detent resistance.

2. 2

   Remove the armrest trim and inspect the wiring harness connecting the encoder to the ACM. Look for pinched wires, loose connector pins, or corrosion.

3. 3

   Connect the Case IH EST and navigate to the ACM advanced configuration. Monitor the live data parameters for the rear hitch controls while turning the knob to see if the voltage/position signal is erratic, frozen, or dropping out.

4. 4

   Check if the Armrest Control Module (ACM) requires a firmware update (e.g., updating to software version 1.1.0.0 or newer) via the EST, which can sometimes resolve false internal failure flags.

1. 1

   Disconnect battery

   Turn off the tractor, remove the key, and disconnect the battery ground cable to prevent electrical shorts.

2. 2

   Remove armrest trim

   Carefully pry or unscrew the upper trim panels of the MultiControl armrest to expose the internal Armrest Control Module (ACM) and switch/encoder sub-assemblies.

3. 3

   Locate encoder

   Locate the hitch settings selector knob encoder on the underside of the control panel.

4. 4

   Disconnect encoder

   Disconnect the electrical pigtail/connector from the faulty encoder.

5. 5

   Remove faulty encoder

   Remove the retaining screws or mounting nut holding the rotary encoder in place and pull the knob/encoder assembly free from the armrest console.

6. 6

   Insert replacement encoder

   Insert the replacement rotary encoder and secure it with the retaining hardware.

7. 7

   Reconnect electrical connector

   Reconnect the electrical connector, ensuring it clicks securely into place.

8. 8

   Reinstall armrest trim

   Reinstall the armrest trim panels.

9. 9

   Reconnect battery

   Reconnect the battery.

10. 10

    Clear codes and calibrate

    Connect the Case IH EST, clear the 518685-00 fault code from the ACM, and perform any necessary hitch control calibrations to sync the new encoder's sweep with the module.