Case IH 4220 - UCM – EHR Controller / UCM: Rear remote no.5 - spool not calibrated

The control module has lost the calibration values for the 5th rear electro-hydraulic remote (EHR) valve, or the position transducer/potentiometer is sending a signal that falls outside of the expected calibrated range. The remote valve will typically be disabled or switched to a failsafe mode.

• MAXXUM T4E
• Magnum MX series (MX180-MX285)
• Magnum 235-340 (Series 4)
• Magnum AFS Connect models
• Puma 165, 180, 195, 210, 225 CVX
• Steiger / Quadtrac 350-620
• Maxxum 110-140 Multicontroller

1. 1

   Check the armrest lever to see if the system thinks the lever is slightly engaged when it is physically in the neutral position (indicates a failing potentiometer)

2. 2

   Inspect the wiring harness and connectors running from the armrest controller to the EHR controller, and from the EHR controller to the rear remote valve #5 for damaged pins, corrosion, or short circuits

3. 3

   Check for valve sticking by ensuring the physical spool inside the rear remote valve is not sticking due to debris or cold/contaminated hydraulic oil

4. 4

   Attempt to recalibrate the valve (primary diagnostic step to rule out software glitches or temporary voltage drops)

1. 1

   Preparation

   Ensure the tractor is parked safely, the engine is running, and the hydraulic oil is brought up to normal operating temperature.

2. 2

   Enter Calibration Mode

   For older models (A-post/EIC): Hold the 'Prog' key while turning the ignition key to the ON position. Navigate to the 'H' menu (specifically H1 or HL for EHR valves). For newer models (AFS Displays): Navigate through the display to the 'Tractor Settings' > 'Calibration' > 'EHR Valves' screen.

3. 3

   Connect Diagnostic Tool (If required)

   On certain older MX/Magnum models, a remote calibration tool/cable (e.g., CAS2806 or 380000488) must be plugged into the diagnostic test port at the back of the cab to monitor load sense signal pressure.

4. 4

   Cycle the Lever

   Follow the on-screen prompts. Typically, you will be asked to pull the #5 EHR lever fully back into the raise/retract detent, push it fully forward into the lower/extend detent, and then let it return to neutral.

5. 5

   Save and Restart

   Once the display indicates the calibration is successful, turn the key off and wait at least 30 seconds for the controller to write the new values to the EEPROM. Restart the tractor to verify the code has cleared.

6. 6

   Part Replacement

   If the calibration fails (e.g., the system hangs on a specific step), replace the EHR lever in the armrest. If the lever is confirmed good, the EHR valve section itself must be replaced.