Case IH 4206 - ACML – ACML: CAN Bus - Engine EEC2 message was not received

The Armrest Control Module is receiving an out-of-range voltage, an invalid encoder signal, or a physically implausible position reading from the joystick that controls the electro-hydraulic remotes.

• MAXXUM T4E
• Case IH Maxxum series
• Case IH Puma series
• Case IH Optum series
• Case IH Magnum series
• Case IH Steiger series

1. 1

   Test the wiring harness continuity from the EHR joystick controls to the ACML controller, and from the controller to the remote valves.

2. 2

   Use the tractor's onboard diagnostics (or Case IH EST diagnostic tool) to check the switch states and voltage divider/5V reference signals coming from the EHR switch panel.

3. 3

   Look for associated armrest codes (e.g., 18007 switch error, 18008 voltage too low, 18009 voltage too high) to determine if the issue is a short to ground or an open circuit.

1. 1

   Attempt Calibration

   Before replacing parts, attempt to recalibrate the EHR joystick. On older models, this is done through the onboard HH menu (navigate to HH > H1 for calibration commands). On newer models (like the Optum), joystick functions are configured and calibrated using the tractor's Case IH Pro 1200 or Pro 700 touchscreen display.

2. 2

   Inspect the ACML

   If calibration fails (e.g., the system locks up and refuses to reach neutral or float), inspect the ACML and the EHR control unit for software updates. Dealers sometimes need to flash new software into the controller.

3. 3

   Replace Faulty Components

   If the harness is intact and calibration fails due to a hard hardware fault (internal encoder failure), the EHR joystick assembly or the ACML itself must be replaced.

4. 4

   Re-calibrate

   Any time an EHR joystick or ACML is replaced, the new component must be calibrated before the hydraulic functions will operate.