Case IH 518595-13 - ACM – ACM: Front hitch working position control sensor disagreement

The electronic draft control system uses a position sensor (potentiometer) to track the angle and movement of the front hitch. This code triggers when the control module detects that the sensor's signal is erratic, missing, or conflicts with the commanded position of the hitch.

• MAGNUM AFS Connect
• Magnum 400 AFS Connect
• Puma

1. 1

   Visually inspect the position sensor body and physical connecting link on the front hitch linkage for breakage, binding, mud, or moisture damage.

2. 2

   Disconnect the sensor and check the pins for corrosion or water ingress.

3. 3

   Verify the wiring harness for an open circuit, short circuit to 12V, or short circuit to ground (0V).

4. 4

   Verify that the sensor is receiving its 5V reference voltage (V REF) and has a solid sensor ground at the connector.

5. 5

   Attempt to recalibrate the front hitch position sensor using the tractor's diagnostic menu, as an uncalibrated potentiometer can cause position disagreement errors.

1. 1

   Park the tractor on a level surface, lower the front hitch completely to relieve hydraulic pressure, and turn off the engine.

   Ensure the machine is safe to work on and hydraulic pressure is relieved.

2. 2

   Locate the front hitch position sensor mounted on the front hitch frame bracket.

   Identify the sensor location for removal.

3. 3

   Disconnect the plug-and-play electrical connector from the sensor.

   Carefully unplug the harness from the sensor.

4. 4

   Remove the mounting hardware (typically M5 bolts and lock nuts) securing the sensor to the bracket.

   Unbolt the sensor from its mounting bracket.

5. 5

   Detach the connecting link and bushing that attach the sensor's rotary arm to the hitch movement mechanism.

   Separate the sensor linkage from the hitch mechanism.

6. 6

   Install the new position sensor (potentiometer), reattaching the bushing and connecting link. Secure the mounting bolts.

   Mount the replacement sensor and reassemble the linkage.

7. 7

   Reconnect the electrical harness.

   Plug the connector back into the new sensor.

8. 8

   Power on the tractor and use the AFS Pro 1200 display (or dealer electronic service tool) to perform a mandatory front hitch calibration.

   This calibration is required so the ACM learns the new sensor's minimum and maximum voltage limits.