Case IH 18312 (518606.02, 518606.07) - ACML – ACML: EHR2 (Electro-Hydraulic Remote 2) Program / Motor Mode Switch Error State

The module is detecting an implausible signal or voltage fluctuation from the EHR2 lever/switch. This is primarily caused by electrical contamination (carbon dust and grease) inside the switch or harness damage inside the armrest. The original software was highly sensitive, triggering a fault if the signal dropped for just 50 milliseconds.

• MAXXUM T4E
• VESTRUM CVX
• Puma
• Maxxum
• Vestrum
• Optum
• Magnum

1. 1

   Open the armrest console and thoroughly inspect the wiring harness leading to the EHR2 lever/switch for any pinched, crushed, or chafed wires.

2. 2

   Use the Case IH Electronic Service Tool (EST) to monitor the voltage output of the EHR2 switch while moving it, looking for erratic jumps or drop-offs in the signal.

3. 3

   Use the EST to check the current software version of the ACML. If it is older than version 3.1, the module is overly sensitive to minor voltage fluctuations.

1. 1

   Repair Wiring

   If the diagnostic check reveals a crushed or damaged harness inside the armrest, repair or replace the affected wiring.

2. 2

   Address the Switch

   If the wiring is intact, the issue is likely internal switch contamination. Attempt to clean the switch contacts with electrical contact cleaner, or replace the affected EHR lever/switch assembly as the most reliable mechanical fix.

3. 3

   Update ACML Software

   Connect the Case IH EST and flash the ACML to the revised software version (v3.1 or newer). The updated software increases the fault detection time threshold from 50 ms to 500 ms, preventing false codes due to minor voltage fluctuations.

4. 4

   Clear and Test

   Clear the inactive fault codes and cycle the EHR2 lever to confirm the repair is successful.