Case IH 518595-09 - ACM – ACM: Front hitch working position control disconnected while powered on

The system has detected an open circuit, loss of communication, or physical disconnection of the front hitch working position control (the dial/potentiometer used to set the front hitch depth/position) while the tractor's electrical system is powered on.

• MAGNUM AFS Connect
• Magnum AFS Connect Series (Models 250, 280, 310, 340, 380, 400, and Rowtrac variants)
• Steiger AFS Connect Series

1. 1

   Inspect the physical connection of the front hitch working position control dial/potentiometer located on the Multicontroller armrest.

2. 2

   Inspect the wiring harness between the working position control and the ACM for any breaks, chafing, or loose/pushed-out pins.

3. 3

   Check for a 5V reference and ground at the sensor/potentiometer connector using a multimeter.

4. 4

   Use the Case IH Electronic Service Tool (EST) or the in-cab AFS Pro 1200 display to monitor the live voltage/percentage of the front hitch working position control. If it reads 0V or an open circuit value, the circuit is broken.

1. 1

   Power Down

   Turn off the tractor, ensure the AFS Pro 1200 display is fully powered down, and disconnect the battery to prevent electrical spikes.

2. 2

   Access the Armrest

   Remove the necessary trim panels on the Multicontroller armrest to access the ACM and the underside of the front hitch controls.

3. 3

   Inspect the Connector

   Locate the front hitch working position control potentiometer/encoder. Disconnect the electrical connector and inspect for corrosion, moisture, or damaged pins. Clean with contact cleaner if necessary.

4. 4

   Test the Sensor

   Test the potentiometer's resistance sweep with a multimeter. If the circuit is open (infinite resistance) across the sweep, the control unit/potentiometer has failed internally and must be replaced.

5. 5

   Test the Harness

   If the sensor tests good, check the continuity of the wiring harness from the sensor connector directly to the ACM connector (e.g., 17-pin connector assignments on the ACM). Repair any broken wires.

6. 6

   Reassembly

   Reconnect all components and restore battery power.

7. 7

   Clear Codes & Calibrate

   Power on the tractor and clear the fault codes using the EST or the AFS Pro display. Perform a front hitch calibration if required by the service manual to ensure the ACM recognizes the full sweep of the position control.