Case IH 522807.13 - ACML – ACML: Logical Program Flow, out of calibration

The control module has detected a software execution error, a mismatch in expected operational parameters, or a loss of calibration values for the armrest controls (such as the Electronic Hydraulic Remote (EHR) levers or joysticks).

• MAXXUM T4E
• VESTRUM CVX
• Case IH Magnum Series (Magnum 260, 290, 235-340 Series 4)
• Case IH Puma Series (Puma 175 CVX)
• Case IH Maxxum Series (Maxxum 125, Maxxum 135 Multicontroller)
• Case IH Steiger Series (Steiger 500 4WD)

1. 1

   Check for accompanying fault codes (such as ARM 129, 4004-ACM, or 4005) which might indicate a hard-wired potentiometer failure or a disconnected EHR valve section.

2. 2

   Inspect wiring and connectors at the Armrest Control Module. Ensure all Tractor Control Unit (TCU) connectors are fully seated, undamaged, and that the pins are tight and in the correct position.

3. 3

   Test potentiometer inputs using the dealer service tool monitor screen. Move the EHR levers and flow control dials to verify if the physical movement matches the data bus status.

4. 4

   Check for software updates, as calibration loss on the ACML is a known issue that can sometimes be caused by outdated software.

1. 1

   Recalibrate the Armrest Controls

   Perform the EHR lever and armrest calibration procedure via the tractor's display monitor.

2. 2

   Clear and Retest

   Once calibration is complete, clear the error code and test the hydraulic remotes and armrest functions for normal operation.

3. 3

   Update ACM Software

   If the calibration aborts, or if the fault code returns after a few days (indicating the module is losing its calibration value), download the correct/latest level of software and flash the ACML using the dealer service tool. After the update, unzip the software package, configure the EHR valve section, and repeat the calibration procedure.

4. 4

   Replace the Module

   If the fault reoccurs after a software update and recalibration, or if the service tool cannot communicate with the ACML, the Armrest Control Module (or the specific failed panel/potentiometer) has suffered an internal hardware failure and must be replaced.

5. 5

   Final Calibration

   Any time a new ACML is installed, a full calibration of the armrest controls must be performed before returning the tractor to service.