Case IH S 0 – Tractor Control Unit (TCU) / Electronic Draft Control (EDC) module: Left load pin failed

The system has detected an invalid signal—such as an open circuit, short circuit, or out-of-range voltage—from the sensor that measures the draft load on the left lower link of the 3-point hitch.

• MX Maxxum
• 7200/8900 series Magnum
• 7110
• 7120
• 7130
• 7140
• 7150
• 7210
• 7220
• 7230
• 7240
• 7250
• 8910
• 8920
• 8930
• 8940
• 8950
• MX80C through MX285
• MXM Series
• Puma Series
• Steiger Series
• Magnum Series

1. 1

   Visually inspect the wiring harness and connectors leading to the left draft pin sensor for moisture, corrosion, or damaged wires (moisture entering the wire hole is a common cause).

2. 2

   Test the wire harness for continuity and verify proper voltage (Pin A is ground, Pin B is the signal input, and Pin C supplies power).

3. 3

   Test the sensor's internal resistance (Pin A to Pin B, and Pin B to Pin C) to confirm if the sensor itself is shorted or open.

4. 4

   Check for mechanical binding to ensure there is no mechanical interference preventing the hitch from moving freely between its minimum and maximum limits.

1. 1

   Prepare tractor

   Park the tractor on a level surface, lower the 3-point hitch completely to remove all mechanical load from the pins, and turn off the engine.

2. 2

   Disconnect sensor

   Disconnect the electrical connector from the left draft pin sensor.

3. 3

   Remove hardware

   Remove the retaining hardware (lock pin or bolt) holding the draft pin in place.

4. 4

   Extract sensor

   Extract the failed draft pin sensor. Note: These pins often become heavily seized due to rust and field debris. You may need to use penetrating oil, a wire brush to clean the exposed areas, and carefully knock the pin loose.

5. 5

   Clean and prep bore

   Thoroughly clean the mounting bore to ensure the new pin will seat correctly. Apply grease or anti-seize compound to the non-sensing surfaces if recommended by the manual.

6. 6

   Install new sensor

   Install the new draft pin sensor and secure it with the retaining hardware.

7. 7

   Reconnect harness

   Reconnect the wiring harness.

8. 8

   Clear codes

   Turn on the tractor and clear the fault codes.

9. 9

   Calibrate hitch

   Perform a hitch calibration procedure (via the tractor's display or calibration switches) to 'zero' the new load cell and map the hitch position command range.

10. 10

    Alternative bypass

    If the tractor is only used for tasks that do not require draft sensing, a Draft Load Sensing Pin Elimination Kit can be installed to simulate a working sensor, permanently clearing the code and disabling draft sensing.