Case IH 5112.09 - ACML – Armrest Control Module (ACML / ACM): Armrest Control Module CAN message timeout error

The Armrest Control Module is experiencing a CAN message timeout error due to an abnormal update rate on the data link. This occurs when a control module is unable to receive expected information from another module within the required timeframe.

• MAXXUM T4E
• VESTRUM CVX
• Maxxum series
• Maxxum 135 Multicontroller
• Magnum series
• MX series
• MX180-270
• MX240
• MX285
• Steiger series

1. 1

   Verify if the armrest is showing an 'ARM OFFLINE' error on the cab display

2. 2

   Open the armrest controller housing and inspect the connectors (such as connector J211) for wiring damage, loose connections, or bent pins

3. 3

   Test the CAN data link wiring, power, and ground circuits for an open or short circuit

4. 4

   Ensure that electrical power is actively being supplied to the Armrest Control Module

5. 5

   Inspect the CAN bus terminators (e.g., the rear terminator) to ensure they have not failed and are not disrupting the update rate

1. 1

   Disconnect the Module

   Open the armrest controller housing and disconnect the main wiring harnesses.

2. 2

   Repair Wiring

   Test the wiring harness for continuity. Repair any damaged wires or bent pins found during the diagnostic phase.

3. 3

   Replace Terminators

   If the wiring is intact but communication is still dropping, replace the CAN terminators.

4. 4

   Evaluate the ACML Board

   If the wiring and terminators are good but the module remains unresponsive (e.g., the board's diagnostic LED stays solid green instead of blinking), the Armrest Control Module itself has likely failed.

5. 5

   Replace the ACML

   Remove the faulty Armrest Control Module and install a new or remanufactured unit.

6. 6

   Calibrate

   Perform a calibration procedure for the armrest components (such as the SCVs) to sync them with the new controller.

7. 7

   Clear Codes

   Clear the fault codes from the system. On some models, this is done by holding the 'DIAG' button while turning the key on, navigating to the ARM menu, and pressing the 'PROG' button to retrieve and clear the faults.