Case IH 14904 – Armrest Control Module (ACM): Armrest Control Module (ACM) missing

The main vehicle network has lost CAN bus communication with the armrest controller. A SwcdAddrClaim message has not been received from the controller, meaning the module is failing to broadcast its presence on the network.

• Puma/Mid Range Magnum
• Maxxum
• MAXXUM T4E
• Case IH Puma series (165, 175, 180, 195, 210, 225 CVX)
• Case IH Steiger series
• Case IH Magnum series
• Case IH MX / TG series

1. 1

   Inspect connectors X009 (CAN instruments), X776 (Armrest Control ARU), and X030 (Diagnosis) for corrosion, backed-out pins, or moisture.

2. 2

   Verify the Armrest Control Module is receiving proper operating voltage (12V) and has a solid ground connection.

3. 3

   Test CAN High and CAN Low lines at the armrest controller for proper voltage (2.5V to 2.7V) and continuity back to the main harness.

1. 1

   Power Down

   Turn off the machine and disconnect the battery to prevent electrical shorts during the repair.

2. 2

   Access the Module

   Remove the access panels on the right-hand operator armrest console to expose the Armrest Control Module (ACM) and its wiring harness.

3. 3

   Inspect and Clean

   Disconnect connectors X009, X776, and X030. Inspect for damage and clean the contacts with electrical contact cleaner. Reconnect and test the machine to see if the code clears.

4. 4

   Replace the Module (if necessary)

   If wiring, power, ground, and CAN lines test good but the module still fails to communicate, the ACM has suffered an internal hardware failure. Unbolt the faulty module and install the replacement unit.

5. 5

   Reassemble and Calibrate

   Reconnect all 17-pin connector assignments to the new ECU. Reinstall the armrest plastics.

6. 6

   Clear Codes

   Reconnect the battery, turn the key on, and use the diagnostic menu or a service tool to clear the 14904 fault code. Verify that all armrest functions (throttle, remotes, PTO) operate correctly.