Case IH 18047 – Armrest Module (ARM / ARU - Arm Rest Unit): EHR (remote valve) 4 lever position - voltage too low

The system is detecting an abnormally low voltage signal from the potentiometer/sensor inside the Electro-Hydraulic Remote (EHR) control lever #4. This typically indicates a failing potentiometer inside the lever assembly, a wiring harness short to ground, or a lost calibration.

• Magnum
• Steiger T4B
• STX Steiger
• Puma
• Maxxum

1. 1

   Check for multiple EHR error codes to determine if the issue is a shared ground or supply voltage problem rather than a single lever failure.

2. 2

   Inspect and clean the main cab ground strap and verify power and ground at the armrest controller to rule out false low-voltage codes.

3. 3

   Attempt to recalibrate the EHR levers via the A-post or Pro700 display before replacing parts.

1. 1

   Power down tractor

   Power down the tractor and disconnect the battery to prevent shorting any armrest electronics.

2. 2

   Remove armrest cover

   Unbolt and remove the cover/panel on the armrest console to access the EHR lever block.

3. 3

   Locate #4 EHR lever

   Locate the #4 EHR lever (often color-coded, e.g., green or blue depending on the specific valve sequence).

4. 4

   Disconnect wire harness

   Disconnect the wire harness connector at the base of the #4 lever.

5. 5

   Remove faulty lever

   Remove the mounting hardware (typically 4 mounting holes on the side of the lever body) and pull the faulty lever cartridge out of the armrest.

6. 6

   Install new lever

   Slide the new EHR lever into position, secure the mounting hardware, and plug in the wire harness.

7. 7

   Reassemble armrest

   Reassemble the armrest panel.

8. 8

   Reconnect battery

   Reconnect the battery and turn the key ON.

9. 9

   Calibrate EHR lever

   Crucial Step: You must perform the EHR lever calibration procedure (via the A-post or Pro700 display) so the Armrest Controller can learn the new lever's specific voltage values for the neutral, extend, and retract positions.