Case IH 518673.02 - ACML – ACML: CAN message (EHR lamps) Data Plausibility Error, unexpected value.

The system is detecting an implausible or unexpected CAN bus message related to the Electro-Hydraulic Remote (EHR) control lamps or lever positions. This typically indicates a communication breakdown, a software glitch, or a hardware failure in the armrest where the EHR levers/joysticks interface with the control module.

• MAXXUM T4E
• VESTRUM CVX
• Magnum Series 235, 250, 260, 280, 290, 310, 315, 340, 370, 380
• Steiger Series 350 to 600
• Puma Series 125, 140, 150, 155, 170, 175, 185, 200, 215, 230
• Maxxum Series 110, 115, 120, 125, 130, 140

1. 1

   Check for accompanying codes related to the Armrest Control Module (e.g., loss of communication codes like 2818 or 2819) or specific EHR lever position errors (e.g., 18255).

2. 2

   Lift the armrest console panel and inspect the wiring harness connecting the EHR levers/joystick to the ACML. Look for pinched wires, chafing, or loose connector pins.

3. 3

   Test EHR lever encoders by verifying their voltage sweeps using a multimeter or the Case IH Electronic Service Tool (EST).

4. 4

   Verify the software version of the Armrest Control Module. OEM software updates may revise the ACML parameters to relax overly sensitive error code detection.

1. 1

   Power Down

   Turn off the tractor, remove the key, and disconnect the battery to prevent electrical shorts while working on the armrest.

2. 2

   Access the ACML

   Remove the screws securing the integrated control panel/armrest cover to expose the internal Electronic Control Unit (ECU) and the EHR lever assemblies.

3. 3

   Clean and Reseat Connectors

   Disconnect the main harness to the ACML and the sub-harnesses to the EHR levers. Clean the contacts with electronic contact cleaner, check for pushed-back pins, and firmly reseat them.

4. 4

   Replace Faulty Components

   If diagnostic testing isolated a specific EHR lever potentiometer/encoder as the source of the erratic data, replace the affected lever assembly. If the wiring is intact and the levers test fine, the Armrest Control Module itself is likely suffering from an internal CAN transceiver failure and must be replaced.

5. 5

   Reassembly

   Install the new module, reconnect all harnesses, and secure the armrest panel.

6. 6

   Calibration and Clearing

   Reconnect the battery. Connect the Case IH EST diagnostic laptop to clear the 518673.02 fault code. You will likely need to flash the latest software to the new ACML and perform an armrest/EHR calibration routine so the module learns the end-stops of the remote levers.