Case IH 517827-02 - ACM – ACM (Armrest Control Module): Manual mechanical front drive switch circuit fault

The control module has detected an electrical circuit malfunction—such as an open circuit, short circuit, or internal failure—originating from the manual Mechanical Front Drive (MFD) / 4WD rocker switch.

• MAGNUM AFS Connect
• Case IH Magnum AFS Connect Series
• Case IH Maxxum
• Case IH Puma

1. 1

   Verify ACM Fault Codes: Check the Armrest Control Module for secondary fault codes that might indicate a broader issue (e.g., ARM 1069 or ARM 8011).

2. 2

   Check ACM Power and Ground: Ensure the ACM itself is receiving proper voltage via unswitched B+ power input (Pin 1), switched B+ power input (Pin 2), and a solid chassis ground (Pin 7).

3. 3

   Inspect the Switch Wiring: Inspect the wiring harness between the switch and the ACM for chafing, pinched wires, or disconnected plugs.

4. 4

   Test the Switch: Perform a continuity test on the MFD rocker switch to determine if the internal contacts have failed.

1. 1

   Power down and disconnect battery

   Power down the tractor and disconnect the battery to prevent electrical shorts while servicing the armrest console.

2. 2

   Remove armrest trim

   Carefully remove the secondary control panel/trim on the Armrest assembly to access the rear of the switches.

3. 3

   Disconnect switch harness

   Locate the manual MFD rocker switch and disconnect its electrical harness connector.

4. 4

   Inspect harness connector

   Inspect the harness connector for pushed-out pins or corrosion. If the connector is in good condition, the fault is likely an internal failure of the switch itself.

5. 5

   Remove faulty switch

   Unclip and remove the faulty MFD switch from the armrest/dashboard mounting slot.

6. 6

   Install new switch

   Snap the new OEM MFD switch into the panel.

7. 7

   Reconnect harness

   Reconnect the electrical harness to the switch.

8. 8

   Reassemble trim

   Reassemble the armrest console trim.

9. 9

   Test and clear codes

   Reconnect the battery, turn the key on, and clear the stored fault codes from the ACM. Test the MFD engagement to ensure the code does not return.