Case IH 18040 – Armrest Controller: EHR (remote valve) 1 lever position - voltage too low

This code indicates that the control module is receiving a voltage signal from the Electro-Hydraulic Remote (EHR) Valve 1 control lever potentiometer that is below the acceptable operating range. This typically points to an open circuit, a short to ground in the wiring harness, or a complete internal failure of the lever's potentiometer.

• Magnum
• Steiger T4B
• Magnum Series
• Steiger / Quadtrac Series
• Puma Series
• Maxxum Multicontroller Series
• Optum Series

1. 1

   Attempt Calibration: Attempt to recalibrate the EHR levers via the A-post display or the Pro700/Pro1200 monitor. If the lever is failing, the calibration will usually fail or the tractor will immediately throw the code again.

2. 2

   Visual & Physical Inspection: Check the physical movement of the EHR 1 lever. Ensure it returns to the neutral position smoothly and isn't physically broken or jammed.

3. 3

   Wiring & Connector Check: Remove the armrest cover and inspect the wiring harness connecting to the EHR 1 lever. Look for pinched wires, chafing, or a disconnected plug.

4. 4

   Voltage Test: Using a multimeter, verify that the potentiometer is receiving its 5V reference voltage and has a good ground from the Armrest Controller.

5. 5

   Swap Test: If the wiring looks good, temporarily swap the electrical connector from the EHR 1 lever to the EHR 2 lever. If the fault code changes to 18042 (EHR 2 lever position - voltage too low), the fault is isolated to the lever itself. If the code remains 18040, the issue is in the wiring harness or the Armrest Controller.

1. 1

   Disconnect Power

   Turn off the tractor ignition and disconnect the battery to prevent electrical spikes.

2. 2

   Access the Armrest Internals

   Remove the retaining screws holding the top cover/trim of the Multicontroller armrest console to expose the EHR lever stack.

3. 3

   Remove the Faulty Lever

   Disconnect the electrical harness connector from the bottom of the EHR 1 lever. Unbolt the retaining screws that secure the EHR 1 lever module to the armrest bracket.

4. 4

   Install the New Part

   Seat the new EHR lever assembly into the bracket and secure it with the mounting screws. Reconnect the electrical harness.

5. 5

   Reassemble

   Reinstall the armrest cover and trim pieces.

6. 6

   Restore Power

   Reconnect the battery and turn the ignition key to the ON position.

7. 7

   Calibrate the New Lever

   You must perform the EHR calibration procedure. Enter the calibration menu (via the A-post or Pro monitor, depending on the model). The system will prompt you to move the lever to its maximum forward (extend) position, maximum rearward (retract) position, and let it rest in neutral. This teaches the Armrest Controller the specific voltage values for the new potentiometer.