Case IH 518559-06 - ACM – ACM: EHR lever A voltage low

The signal voltage from the Electro-Hydraulic Remote (EHR) lever potentiometer has dropped below the acceptable lower voltage limit (typically below the 5-volt reference threshold). This indicates a short to ground, an open circuit in the signal wire, a failed 5V reference circuit, or a faulty EHR lever potentiometer.

• MAGNUM AFS Connect
• Magnum Series
• Steiger Series
• Puma Series
• Maxxum Series

1. 1

   Check the 5V Reference: Verify that the ACM is supplying the 5V reference to the EHR lever (Circuit 5520A/B/G/H).

2. 2

   Check the Sensor Ground: Ensure the ground circuit (Circuit 60A) is intact and not open.

3. 3

   Check the Signal Wire: Inspect the EHR potentiometer signal wire (Circuit 5551) for a short to ground or an open circuit between the lever and the ACM.

4. 4

   Software/Calibration Check: Check if the EHR lever has been recently calibrated. A loss of calibration can sometimes trigger out-of-range voltage errors.

1. 1

   Attempt Calibration

   Enter the tractor's H-Menu or Electronic Instrument Cluster (EIC) diagnostic mode. Press the CRPM switch to activate the EHR lever calibration mode (the display will show "R1" or the respective lever number).

2. 2

   Recalibrate

   Perform the EHR lever calibration procedure. If the lever was not calibrated after a recent controller change, this may resolve the issue.

3. 3

   Software Update

   If the error code persists after calibration, download and flash the correct/latest level of software to the ACM, then repeat the calibration procedure.

4. 4

   Component Replacement

   If the fault occurs again after software updates and recalibration, the internal potentiometer in the lever has failed. Remove the armrest panel and replace the faulty EHR lever assembly.

5. 5

   ACM Replacement

   If a new lever does not resolve the issue and the wiring harness tests good, the Armrest Control Module itself must be replaced.