Case IH 518557-00 - ACM – ACM: EHR settings adjustment knob internal failure

Internal electrical or mechanical failure within the rotary knob used to adjust the Electro-Hydraulic Remote (EHR) valve settings. The system detects that the encoder/potentiometer inside the knob is sending an erratic, out-of-range, or non-existent signal when turned.

• MAGNUM AFS Connect
• Case IH Magnum AFS Connect Series: 250, 280, 310, 340, 380, and 400 (Wheeled and Rowtrac)
• Case IH Steiger / Quadtrac AFS Connect Series: 370, 420, 470, 500, 540, 580, 620

1. 1

   Physical Inspection: Open the armrest compartment and inspect the EHR settings adjustment knob. Check for physical binding, sticking, or lack of detent feel when rotating the knob.

2. 2

   Wiring & Connection Check: Lift the armrest control panel and inspect the wiring harness connecting the knob assembly to the ACM. Look for pinched wires, loose pins, or corrosion at the connector.

3. 3

   EST (Electronic Service Tool) Monitoring: Connect the Case IH EST laptop. Navigate to the ACM inputs and monitor the live data for the EHR settings knob. Slowly rotate the knob clockwise and counterclockwise. If the value jumps erratically, stays at 0, or stays at a maximum value regardless of physical movement, the internal encoder has failed.

4. 4

   Check for Related Codes: Ensure there are no overarching 5-volt reference codes or CAN communication codes (e.g., 2818 - Loss of communication with ACM) that might be causing a false flag for the knob.

1. 1

   Power Down

   Turn off the tractor, remove the key, and disconnect the negative battery cable to prevent electrical shorts.

2. 2

   Access the Armrest Panel

   Open the armrest storage compartment. Remove the Torx/Phillips retaining screws securing the upper control panel bezel to the armrest base.

3. 3

   Lift and Disconnect

   Carefully lift the control panel assembly. Locate the specific electrical connector for the EHR settings adjustment knob/sub-panel and disconnect it.

4. 4

   Remove the Component

   Depending on the specific armrest configuration, the knob may be held in by retaining clips or small screws on the underside of the panel. Remove the fasteners and push the faulty knob assembly out. (Note: On some AFS Connect armrests, the EHR knob is integrated into a larger sub-module circuit board that must be replaced as a single unit).

5. 5

   Install the New Part

   Seat the new knob/module into the panel and secure it with the retaining screws or clips.

6. 6

   Reassemble

   Reconnect the electrical harness, ensuring the connector clicks into place. Lower the control panel back into the armrest and reinstall the retaining screws.

7. 7

   Test and Calibrate

   Reconnect the battery. Turn the key on and use the AFS Pro 1200 display to navigate to the EHR settings screen. Rotate the new knob to verify that the valve flow rate values increase (clockwise) and decrease (counterclockwise) smoothly. Clear the inactive 518557-00 code using the EST.