Case IH 18256 (517816.03, 517816.04, 518561.02, 518561.03, 518561.04) - ACML – ACML: EHR3 Lever Position ACML - error state

This fault indicates a signal failure, out-of-range reading, or erratic voltage from the Electro-Hydraulic Remote (EHR) valve 3 control lever on the operator's armrest. It is commonly caused by either a software sensitivity issue where minor voltage fluctuations trigger false codes due to a short error detection time, or a hardware failure where internal rivet pillars cause friction and contaminate the sensor contacts.

• MAXXUM T4E
• VESTRUM CVX
• Puma series
• Puma 200
• Vestrum CVXDrive
• Maxxum
• Magnum series
• Steiger series

1. 1

   Check the Wiring Harness: Inspect the wiring harness and connectors under the armrest leading to the EHR3 lever. Look for crushed, pinched, or damaged wires caused by poor factory routing.

2. 2

   Check for Contamination: Inspect the lever connector for electrical contamination, corrosion, or poor pin contact.

3. 3

   Check Software Version: Connect the electronic diagnostic tool (EST) and check the current software version of the ACML. If it is older than version 3.0/3.1, a software update is required.

1. 1

   Update the ACML Software

   Flash the Armrest Control Module with software version 3.1 (or newer). This revised software relaxes the error code parameters by increasing the fault detection time from 50ms to 500ms, which prevents minor voltage fluctuations from triggering the 18256 code.

2. 2

   Repair Harness Routing

   If the wiring harness under the armrest is pinched or damaged, repair the broken wires and reroute the harness so it is not crushed by the armrest plastics.

3. 3

   Replace the EHR Lever

   If the software update and wiring checks do not resolve the issue, the internal carbon film of the EHR3 lever is likely damaged by friction. You must disassemble the armrest control panel and replace the EHR3 lever assembly with the updated part (Case IH sourced these from a new supplier to fix the tolerance issue).

4. 4

   Calibrate and Clear

   After replacing the lever, turn the key ON, clear the inactive fault codes via the A-post display or EST tool, and perform the remote valve calibration procedure so the ACML learns the new lever's neutral, extend, and retract positions.