Case IH 518434-06 - ACM – ACM: Multi function handle thumbwheel voltage low

The signal voltage from the thumbwheel on the Multi-Function Handle (MFH) has dropped below the acceptable minimum threshold.

• MAGNUM AFS Connect
• Magnum 250
• Magnum 280
• Magnum 310
• Magnum 340
• Magnum 380
• Magnum 400
• Magnum Rowtrac
• Steiger AFS Connect Series
• Quadtrac AFS Connect Series

1. 1

   Inspect the wiring harness and connectors between the Multi-Function Handle and the Armrest Control Module (ACM) for pinched wires, corrosion, or pushed-out pins

2. 2

   Verify that the ACM is supplying the correct 5V reference voltage and a solid ground to the Multi-Function Handle sensors

3. 3

   Test the specific signal wire for the thumbwheel to ensure it is not shorted to ground, which would pull the voltage low

4. 4

   Connect the Case IH Electronic Service Tool (EST) or use the AFS Pro 1200 display diagnostics screen to monitor the live voltage or percentage of the thumbwheel. If voltage remains stuck low while rolling the thumbwheel and wiring is intact, the internal sensor has failed

1. 1

   Turn off the tractor, place the transmission in Park, and disconnect the battery to prevent electrical spikes.

   Turn off the tractor, place the transmission in Park, and disconnect the battery to prevent electrical spikes.

2. 2

   Carefully remove the trim panels on the Multicontroller armrest to access the base of the Multi-Function Handle and the ACM.

   Carefully remove the trim panels on the Multicontroller armrest to access the base of the Multi-Function Handle and the ACM.

3. 3

   Disconnect the main electrical harness connector linking the Multi-Function Handle to the ACM.

   Disconnect the main electrical harness connector linking the Multi-Function Handle to the ACM.

4. 4

   Unbolt the mounting hardware securing the Multi-Function Handle to the armrest structure and remove the faulty handle.

   Unbolt the mounting hardware securing the Multi-Function Handle to the armrest structure and remove the faulty handle.

5. 5

   Install the replacement Multi-Function Handle and secure the mounting hardware.

   Install the replacement Multi-Function Handle and secure the mounting hardware.

6. 6

   Reconnect the electrical harness, ensuring the connector clicks fully into place to prevent future communication codes.

   Reconnect the electrical harness, ensuring the connector clicks fully into place to prevent future communication codes.

7. 7

   Reinstall the armrest trim panels.

   Reinstall the armrest trim panels.

8. 8

   Reconnect the battery and power on the tractor.

   Reconnect the battery and power on the tractor.

9. 9

   Use the EST or the AFS Pro 1200 display to clear the 518434-06 fault code from the ACM. Test the thumbwheel to ensure target speed adjustments register correctly on the display.

   Use the EST or the AFS Pro 1200 display to clear the 518434-06 fault code from the ACM. Test the thumbwheel to ensure target speed adjustments register correctly on the display.