Case IH 518413-03 - ACM – ACM: Display navigation knob voltage high

The system is detecting that the electrical signal voltage from the display navigation knob (the dial button encoder on the armrest) is higher than the maximum allowable threshold. This typically indicates an open circuit, a short to a power source, or an internal failure of the encoder itself.

• MAGNUM AFS Connect
• Magnum AFS Connect Series (Models 180, 200, 220, 240, 250, 280, 310, 340, 380, 400)
• Steiger & Quadtrac AFS Connect Series
• Optum AFS Connect Series

1. 1

   Inspect the wiring harness connecting the Armrest Control Module (ACM) to the dial button encoder. Look for chafed wires, pinched harnesses inside the armrest assembly, or loose connectors.

2. 2

   Disconnect the encoder and inspect the pins for corrosion, moisture, or pushed-back terminals.

3. 3

   Using a multimeter, verify that the encoder is receiving the correct reference voltage and has a solid ground.

4. 4

   Test the signal wire between the encoder and the ACM for continuity. Check for a short to power (which would directly cause a 'voltage high' condition) or an open circuit.

5. 5

   If the wiring harness, reference voltage, and ground all test within specification, the internal circuitry of the navigation encoder has failed and the unit must be replaced.

1. 1

   Power Down

   Turn off the tractor ignition, remove the key, and disconnect the negative battery cable to prevent electrical shorts during repair.

2. 2

   Disassemble Armrest Trim

   Carefully pry up or unscrew the upper trim panels on the Multicontroller armrest to gain access to the underside of the control console.

3. 3

   Remove the Encoder

   Locate the dial button encoder (navigation knob) assembly. Disconnect its electrical harness connector.

4. 4

   Unmount the Unit

   Remove the retaining screws or mounting clips holding the encoder to the armrest housing and pull the faulty unit out.

5. 5

   Install the New Part

   Seat the new encoder into the armrest housing and secure it with the retaining hardware.

6. 6

   Reconnect

   Plug the electrical harness back into the new encoder, ensuring the connector clicks and locks into place.

7. 7

   Reassemble

   Snap or screw the armrest trim panels back into their original positions.

8. 8

   Test

   Reconnect the battery, turn the ignition on, and allow the AFS Pro 1200 display to boot up. Use the new navigation knob to scroll through the menus to verify functionality. Check the diagnostic menu to ensure fault code 518413-03 has moved to an "inactive" state, and clear it from the ACM memory.