Case IH 4127 – EHR (Electro-Hydraulic Remote) Controller or Armrest Control Module (ACM / ARU): Rear Remote No.2 - Spool Not in Neutral When Switched On

When the tractor's ignition is turned on, the controller detects that the spool for the second rear auxiliary hydraulic remote is not resting in its center (neutral) position, or the electrical signal from the armrest lever is telling the controller it is out of neutral. As a safety mechanism, the system will lock out the hydraulic functions for that remote until the tractor is restarted and the fault is cleared.

• Magnum
• Maxxum
• Steiger T4B
• MAXXUM T4E
• VESTRUM CVX
• Magnum Series
• Steiger / Quadtrac Series
• Puma Series
• Maxxum Series
• Optum Series

1. 1

   Verify that the Remote No. 2 lever/switch on the armrest is not physically stuck and springs back to the exact center (neutral) position.

2. 2

   Check if the EHR lever potentiometer has drifted out of calibration (system thinks switch is stroked when physically centered).

3. 3

   Check the solenoid cartridge torque on the No. 2 valve at the rear EHR valve block (maximum installation torque is typically 9 ft-lbs; over-tightening can bind the spool).

4. 4

   Inspect the wiring harness between the armrest and the rear EHR valve for corrosion, shorts, or open circuits.

1. 1

   Attempt Calibration

   Before replacing parts, attempt to recalibrate the EHR levers. For A-Post Display models: Hold the PROG key while turning the ignition key to the ON position (engine off). Navigate to the 'ARM' section to find the calibration menu. Pull the remote levers fully back, then fully forward, then let them return to neutral. Turn off the key and wait 30 seconds before restarting. For Pro 1200 / AFS Displays: Follow the on-screen EHR calibration procedure in the hydraulic settings menu.

2. 2

   Replace the Armrest Switch

   If the calibration fails, or if the green cylinder light on the A-post stays illuminated when the lever is centered, the potentiometer inside the armrest lever is likely failing and the lever assembly must be replaced.

3. 3

   Inspect the EHR Valve Pilot Head

   If the armrest switch is functioning correctly, the issue is at the rear valve block. Remove the pilot head (actuator) from the No. 2 remote valve. Check for debris, corrosion, or a sticking main spool.

4. 4

   Replace the Pilot Head / Spool

   If the spool is binding or the pilot head has failed electrically, replace the pilot head assembly. (Note: If the tractor is used for high-demand continuous flow like a planter vacuum fan, Case IH recommends upgrading to a modified main spool with an additional hydraulic bleed to prevent surging and sticking).

5. 5

   Reassign Valve Addresses

   If the pilot head is replaced, you must perform a renumbering/reassignment procedure so the controller knows which lever controls the newly installed valve.

6. 6

   Clear Codes

   Clear the fault codes using the Electronic Service Tool (EST) or in-cab display and test the remote for proper operation.