Case IH 18028 – Armrest Control Module (ACM): EHR 5 lever position - voltage too high

The control module is detecting that the voltage signal coming from the Electronic Hydraulic Remote (EHR) lever #5 position sensor (potentiometer) is exceeding the maximum expected threshold (typically indicating a short to power or an open ground). If the tractor is not physically equipped with a 5th remote valve, this fault code is a software issue indicating incorrect configuration of the ACM.

• Magnum
• Steiger T4B
• Magnum Series
• Puma Series
• Steiger Series
• Maxxum Series
• MX/TG Series

1. 1

   Verify Tractor Configuration: Physically check the armrest to see if the tractor is actually equipped with a 5th EHR lever.

2. 2

   If NO 5th lever is present: Do not tear down the armrest. The issue is strictly a software configuration error in the ACM.

3. 3

   If a 5th lever IS present: Check the wiring harness between the EHR 5 lever and the ACM for chafing, pinched wires, or a short to a 5V/12V power source.

4. 4

   If a 5th lever IS present: Check the ground circuit for the EHR 5 potentiometer for an open circuit.

5. 5

   If a 5th lever IS present: Test the EHR 5 lever potentiometer for a smooth, linear voltage sweep.

6. 6

   If a 5th lever IS present: Check if the EHR lever simply lost its calibration parameters.

1. 1

   Connect diagnostic tool

   Scenario A (The tractor does NOT have a 5th EHR Lever): Connect the CNH Electronic Service Tool (EST) to the tractor's diagnostic port.

2. 2

   Navigate to settings

   Navigate to the ACM (Armrest Control Module) advanced configuration settings.

3. 3

   Locate parameter

   Locate the parameter for EHR 5 (e.g., Config B/b 5.3 "EHR 5 lever position").

4. 4

   Change configuration

   Change the configuration setting to indicate that the 5th lever is "Not Installed" or disable it.

5. 5

   Save and clear

   Save the configuration, cycle the key power, and clear the fault codes.

6. 6

   Disconnect battery

   Scenario B (The tractor DOES have a 5th EHR Lever): Disconnect the battery to prevent electrical spikes.

7. 7

   Remove covers

   Remove the armrest console covers to access the underside of the EHR levers.

8. 8

   Inspect wiring

   Inspect the wiring pigtail and connector for EHR lever #5. Repair any broken wires, clean corroded pins, and ensure the connector is seated tightly.

9. 9

   Replace parts

   If the wiring is intact, the potentiometer inside the lever has failed internally. Replace the EHR 5 lever potentiometer or the complete EHR lever assembly.

10. 10

    Reassemble

    Reassemble the armrest and reconnect the battery.

11. 11

    Perform calibration

    Mandatory Calibration: Perform the EHR lever calibration procedure. This can be done via the tractor's display (EIC) or the EST so the ACM can learn the new potentiometer's neutral, maximum extend, and maximum retract voltage limits.