Case IH 2818 – Trans (Transmission Control Unit / TCU): Communication lost with the Armrest Control Module (ACM)

The tractor's main network (CAN bus) has lost the data signal from the electronic control unit that manages the armrest controls (which includes the multi-function handle, electrohydraulic remote levers, and PTO controls).

• Magnum
• Steiger T4B
• Case IH Magnum Series
• Case IH STX Steiger Series
• Case IH Puma Series

1. 1

   Check for accompanying Armrest Control Module (ACM) error codes, which may indicate a loss of power or ground causing the module to drop off the CAN bus.

2. 2

   Inspect the CAN bus wiring harness and the 17-pin connector assignments at the ACM for loose connections, corrosion, or damaged wires.

3. 3

   Verify the ACM is receiving its required 12-volt input power and has a proper ground.

4. 4

   Clear the error code using an Electronic Service Tool (EST) and cycle the power to determine if the communication loss was a momentary glitch or a hard failure.

1. 1

   Diagnose failure

   If the fault reoccurs after clearing and there are no other ACM-specific error codes present, the module itself or the associated EHR (Electro-Hydraulic Remote) valve section has failed internally.

2. 2

   Disconnect battery

   Disconnect the battery to observe electrostatic discharge precautions.

3. 3

   Access module

   Remove the armrest paneling to access the Armrest Control Module (ECU).

4. 4

   Disconnect harnesses

   Disconnect the 17-pin wiring harnesses from the module.

5. 5

   Replace module

   Remove and replace the Armrest Control Module.

6. 6

   Configure and calibrate

   The new module must be configured and calibrated to the tractor (including calibrating the levers at power-up) using the Case IH Electronic Service Tool (EST).

7. 7

   Clear code and test

   Clear the 2818 error code and test the system for normal operation.