Case IH 518676-13 - ACM – ACM: Hitch settings selector knob disconnected

The "-13" failure mode identifier specifically indicates an out-of-calibration or disconnected state (open circuit) between the selector knob and the control module.

• MAGNUM AFS Connect
• Magnum 400 AFS Connect

1. 1

   Open the armrest console and verify that the electrical connector to the Hitch Settings Selector Knob is securely plugged in.

2. 2

   Inspect the wiring harness between the selector knob and the ACM for backed-out pins, corrosion, or broken wires. Ensure the ACM's 46-pin and 30-pin main connections are seated properly.

3. 3

   Use a multimeter to check for continuity across the hitch settings selector knob terminals while actuating it. Infinite resistance indicates internal failure.

4. 4

   Verify that the ACM is supplying the correct reference voltage and ground to the switch circuit.

1. 1

   Turn off the tractor and disconnect the battery

   to prevent electrical shorts.

2. 2

   Disassemble the upper armrest console

   to gain access to the ACM and the operator switches.

3. 3

   Locate the Hitch Settings Selector Knob assembly.

4. 4

   If the connector is simply unplugged, reconnect it securely and ensure the locking tab engages.

5. 5

   If the wiring is damaged, repair the broken wire or replace the affected harness section.

6. 6

   If the switch failed the continuity test, remove the retaining clips/screws holding the knob assembly to the armrest bezel and install a new switch.

7. 7

   Reassemble the armrest console.

8. 8

   Reconnect the battery and power on the tractor.

9. 9

   Connect the Case IH Electronic Service Tool (EST) to clear the inactive 518676-13 fault code and verify that the ACM is reading the knob's inputs correctly.