Case IH 520613-01 - ACM – ACM: Rear hitch working position internal failure

The signal from the rear hitch position control potentiometer (or rockshaft position sensor) is out of tolerance, shorted internally, or the control module itself has suffered an internal hardware failure.

• MAGNUM AFS Connect
• Case IH Magnum Series
• Case IH STX Steiger Series
• Case IH Puma Series

1. 1

   Check the mechanical linkage connected to the rockshaft position potentiometer to ensure it is not physically misadjusted, bent, or damaged.

2. 2

   Inspect the wiring harness between the rear hitch position sensor and the ACM for breaks (Open Load), shorts to ground, or shorts to battery voltage.

3. 3

   Check for loose connectors, moisture intrusion, or bent pins at both the sensor plug and the ACM harness.

4. 4

   Attempt to recalibrate the rear hitch position sensor using the tractor's display or dealer service tool.

5. 5

   Verify if the ACM has an internal failure by confirming wiring, linkage, and sensor test good but the code persists.

1. 1

   Adjust Linkage

   If the mechanical linkage is misadjusted, adjust the mechanical linkage for the rockshaft/hitch position potentiometer to the correct factory specifications.

2. 2

   Recalibrate

   Perform a recalibration of the hitch load/position potentiometer. If the calibration is successful and the code clears, return the tractor to service.

3. 3

   Repair Wiring

   If wiring damage or bent pins were found during the diagnostic checks, repair the damaged wiring harness or replace the connector pins.

4. 4

   Replace Sensor

   If the potentiometer has failed internally (shorted load) and will not take a calibration, replace the rear hitch position control potentiometer.

5. 5

   Replace ACM

   If all external components and wiring are verified as functional, the ACM has suffered an internal failure. Replace the Armrest Controller Module and perform a full module reconfiguration and calibration.