Case IH 1068 - UCM – UCM: Height limit control not set to maximum during calibration

Triggered during the Electronic Draft Control (EDC) or rear hitch calibration procedure. It indicates that the system detects the height limit control knob (potentiometer) is not turned to its maximum (fully clockwise) position, which is a strict prerequisite for the calibration sequence to complete successfully.

• VESTRUM CVX
• Puma
• Magnum
• Maxxum
• Farmall

1. 1

   Ensure the height limit control knob on the armrest/EDC panel is turned fully clockwise to its absolute maximum setting.

2. 2

   Enter the tractor's diagnostic/H-menu and check the displayed potentiometer reading during calibration. If the knob is fully clockwise but the screen does not show the maximum value, the sensor is failing.

3. 3

   Check the wiring harness and connector leading to the height limit control potentiometer for corrosion, open circuits, or shorts to ground/power.

1. 1

   Attempt Proper Calibration

   Turn the ignition ON and enter the calibration menu (often the H8 or H3 procedure depending on the model). Turn the height limit control knob fully clockwise. Start the engine while holding down the fast raise switch on the Multi-Function Handle (MFH) for three to ten seconds to initiate the sequence. Fully raise and then lower the hitch using the position control lever on the armrest. Turn the ignition off to store the calibration value.

2. 2

   Replace the Potentiometer (If Code Persists)

   Disconnect the tractor's battery. Remove the armrest control console cover or the specific EDC panel housing the rotary dials. Disconnect the 3-pin weather-proof connector from the back of the height limit control potentiometer. Remove the retaining nut/screws and pull the faulty rotary sensor out of the panel. Install the new OEM potentiometer, secure it, and plug in the connector. Reassemble the armrest console. Re-run the hitch calibration procedure to clear the code and restore normal EDC operation.