Case IH 518595-01 - ACM – ACM: Front hitch working position internal failure

The system has detected an internal failure, signal loss, or out-of-range voltage from the front hitch position sensor (potentiometer) circuit, preventing the system from accurately determining the height and working position of the front hitch.

• MAGNUM AFS Connect
• Magnum 250 AFS Connect
• Magnum 280 AFS Connect
• Magnum 310 AFS Connect
• Magnum 340 AFS Connect
• Magnum 380 AFS Connect
• Magnum 400 AFS Connect

1. 1

   Visually inspect the front hitch position sensor (potentiometer) and its mechanical linkage rod on the front rockshaft to ensure it is not disconnected, bent, or seized.

2. 2

   Inspect the wiring harness connecting the front hitch position sensor to the ACM for damaged wires, and check connector ends for bent, corroded, or dislocated pins.

3. 3

   Perform a potentiometer sweep test: with the engine off, disconnect the mechanical linkage, and use a multimeter to measure resistance while manually moving the sensor arm. Look for dropouts, dead spots, or infinite resistance indicating internal failure.

4. 4

   Verify if the hitch controller lost its calibration parameters due to external electromagnetic interference or a dead spot by attempting to recalibrate the hitch.

1. 1

   Prepare the tractor for repair

   Park the tractor on a level surface, lower the front hitch to the ground (if possible to relieve hydraulic pressure), turn off the engine, and engage the parking brake.

2. 2

   Locate the sensor

   Locate the front hitch position sensor on the right side of the front hitch assembly.

3. 3

   Disconnect the electrical connector

   Disconnect the electrical connector from the sensor.

4. 4

   Unbolt the mechanical linkage

   Unbolt the mechanical linkage rod that connects the rockshaft to the sensor arm.

5. 5

   Remove the faulty sensor

   Remove the mounting bolts securing the faulty position sensor and remove the unit.

6. 6

   Install the new sensor

   Install the new position sensor and tighten the mounting hardware.

7. 7

   Reattach the mechanical linkage

   Reattach the mechanical linkage rod to the new sensor's arm.

8. 8

   Reconnect the electrical connector

   Reconnect the electrical connector, ensuring the weather seal is intact and the plug clicks into place.

9. 9

   Perform Hitch Calibration

   Start the tractor and perform a mandatory Hitch Calibration procedure using the AFS Connect monitor or the Electronic Service Tool (EST). Note during calibration: The engine speed must be maintained above 1500 RPM, and the tractor must remain completely stationary. If the tractor moves, the calibration will abort and throw a secondary 9320 fault code.