Case IH 518423-13 - ACM – ACM: Hand throttle 2 sensor disagreement

The control module is receiving a voltage signal from the secondary hand throttle position sensor (potentiometer) that does not match the expected parameters or disagrees with the primary sensor, indicating that the sensor is either out of calibration, failing, or experiencing a wiring fault.

• MAGNUM AFS Connect
• Case IH Magnum AFS Connect series
• Steiger AFS Connect series

1. 1

   Remove the armrest cover and inspect the wiring harness leading to the hand throttle assembly for pinched wires, chafing, or disconnected pins.

2. 2

   Using a multimeter, verify that the sensor is receiving a steady 5-volt reference and has a solid ground from the ACM.

3. 3

   Monitor the signal voltage while slowly moving the hand throttle from idle to full throttle. The voltage should scale smoothly without dropping out or spiking.

4. 4

   Attempt to recalibrate the hand throttle using the Case IH Electronic Service Tool (EST) laptop or through the tractor's AFS Pro display calibration menu before condemning the part.

1. 1

   Power Down

   Turn off the tractor, remove the key, and disconnect the battery ground cable to prevent electrical shorts.

2. 2

   Access the Armrest

   Carefully pry or unscrew the upper trim panels of the MultiControl armrest to expose the internal joystick and throttle mechanisms.

3. 3

   Locate the Sensor

   Locate the hand throttle lever assembly. The potentiometer is mounted directly to the side of the throttle pivot axis.

4. 4

   Disconnect

   Unplug the electrical connector from the hand throttle potentiometer.

5. 5

   Remove the Sensor

   Remove the retaining screws (often M4 hex socket head screws) that secure the potentiometer to the throttle housing.

6. 6

   Install the New Part

   Seat the new potentiometer onto the pivot shaft, ensuring the internal tang aligns correctly with the throttle lever slot. Secure it with the retaining screws.

7. 7

   Reassemble

   Reconnect the wiring harness and reinstall the armrest trim panels.

8. 8

   Recalibrate

   Reconnect the battery. You must connect the Case IH EST (Electronic Service Tool) to perform an ACM configuration and calibrate the new "Hand throttle #2 position" sensor so the module learns the new minimum and maximum voltage values.