Case IH 520613-00 - ACM – ACM: Rear hitch working position internal failure

Internal electrical or mechanical failure of the rear hitch position control potentiometer/encoder.

• MAGNUM AFS Connect
• Magnum 250 AFS Connect
• Magnum 280 AFS Connect
• Magnum 310 AFS Connect
• Magnum 340 AFS Connect
• Magnum 380 AFS Connect
• Magnum 400 AFS Connect

1. 1

   Inspect the rear hitch position control knob/slider on the armrest for physical damage, binding, or sticking.

2. 2

   Access the underside of the armrest console and inspect the wiring harness connecting the hitch position potentiometer to the ACM for loose connections, backed-out pins, or corrosion.

3. 3

   Connect the Case IH EST and monitor live data for the rear hitch position control potentiometer while moving the control; look for dropouts, spikes, or 'ERROR' readings indicating a failed internal track.

4. 4

   Check for accompanying voltage codes (e.g., 18014 or 18015) to confirm if the circuit is shorting out or open.

1. 1

   Power Down

   Turn off the tractor and disconnect the negative battery cable to prevent electrical shorts while working inside the armrest.

2. 2

   Disassemble the Armrest

   Remove the retaining screws securing the top cover or side panels of the operator armrest console to access the internal ACM and control switches.

3. 3

   Remove the Faulty Control

   Locate the rear hitch working position potentiometer assembly. Disconnect its electrical harness connector.

4. 4

   Unmount the Potentiometer

   Remove the mounting screws or retaining clips holding the potentiometer/encoder to the armrest bezel.

5. 5

   Install the New Part

   Seat the replacement hitch position control potentiometer into the armrest and secure it with the retaining hardware.

6. 6

   Reassembly

   Reconnect the electrical harness to the new sensor and reassemble the armrest console covers.

7. 7

   Calibration

   Reconnect the battery. Turn the key on and use the Case IH EST (or the AFS Pro display, if supported via the diagnostic menu) to perform a calibration of the armrest controls so the ACM learns the new minimum and maximum voltage values of the replacement potentiometer. Clear the 520613-00 fault code.