Case IH R31 – EHR (Electronic Hydraulic Remote) Control Unit: EHR Control Unit 3 Float Switch Error

Indicates an electrical fault, signal failure, or calibration issue specifically tied to the float switch circuit for the Electronic Hydraulic Remote (EHR) Valve #3.

• MXM
• Case IH MXM Series
• MXM 120
• MXM 130
• MXM 140
• MXM 155
• MXM 175
• MXM 190
• Case IH Magnum Series
• Case IH Puma Series

1. 1

   Perform a Switch Diagnostic Test in the H-Menu (menu H5 on the U1 controller) by actuating the EHR 3 float switch and listening for an audible tone.

2. 2

   Conduct a wiggle test on the wiring harness connected to the hand controller/armrest and the EHR valve while listening for the diagnostic tone to locate intermittent shorts or breaks.

3. 3

   Check CAN bus resistance by disconnecting a remote valve connector and measuring between terminals 2 and 3 (blue and red wires); it should read approximately 120 Ω.

4. 4

   Verify the 5-volt reference signal to the EHR valve is within limits and ensure the spool travel potentiometer is not shorted to ground.

1. 1

   Resolve Wiring/Switch Faults

   Repair any broken wires or replace the faulty float switch / hand controller module if the switch failed the H-Menu diagnostic test.

2. 2

   Valve Replacement (If Necessary)

   If the switch and wiring are intact but the EHR valve 3 output stage or transducer is faulty, replace the EHR PWM solenoid valve or the complete EHR spool valve assembly.

3. 3

   Mandatory Calibration

   If a mechanical repair is performed, a PWM solenoid valve is replaced, a potentiometer is replaced, or the non-volatile memory has been reset, you must recalibrate the EHR system.

4. 4

   Calibration Process

   Enter the calibration mode (often HA mode). The display will guide you through acquiring the neutral position (display shows '1'), then moving the lever to the raise position (display shows '2'), and finally the float position. The program lights will illuminate as each position is successfully stored.