Case IH 31 – TMF (Tractor Management Function) Controller, Hitch Controller, or Armrest Controller Module (ACM / ATC): Left Draft Pin voltage is outside the normal operating range

The electronic draft control (EDC) system uses draft pin sensors on the lower link arms to measure the pulling force of an implement. This code triggers when the controller detects a voltage signal from the left-hand sensor that falls outside the calibrated specification, pointing to an open circuit, a short to ground, moisture intrusion, or an internal failure of the sensor coil.

• Magnum
• Magnum Series
• MX Magnum Series
• Magnum Small/Large Frame (Tier 4)
• TG Series Tractors

1. 1

   Inspect the wiring harness and the sensor connector (Pins A, B, and C) for damaged wires, corrosion, or water intrusion.

2. 2

   Test sensor resistance across its pins. Depending on the generation, resistance should be around 3k ohms (newer models) or 175k–185k ohms (older 7100/7200 series). A reading near 0 indicates an internal short, while infinite resistance indicates an open circuit.

3. 3

   Verify tractor configuration to ensure the armrest controller hasn't been incorrectly calibrated for draft control if the tractor is not equipped with it.

1. 1

   Disconnect wiring

   Disconnect the wiring harness from the left draft pin sensor.

2. 2

   Remove retaining hardware

   Remove the heavy outside retaining plate, lock pins, or snap rings holding the draft pin in the lower link arm support.

3. 3

   Remove faulty draft pin

   Remove the faulty draft pin. Note: These are often seized in the blind hole due to rust and dirt. You may need to drive a wedge between the sensor and the frame, or use a heavy punch to drive it out.

4. 4

   Install new sensor

   Clean the bore, install the new EDC draft pin sensor, and secure the retaining hardware.

5. 5

   Reconnect wiring

   Reconnect the wiring harness.

6. 6

   Calibrate hitch

   Perform a hitch calibration via the tractor's display/armrest controller so the system can learn the new sensor's base voltage.

7. 7

   Bypass system (Optional)

   If you do not use draft control, you can bypass the system by unplugging the failed left draft pin sensor and plugging a Draft Pin Eliminator Kit directly into the tractor's wiring harness.

8. 8

   Secure eliminator kit

   Zip-tie the eliminator kit safely up under the cab to protect it from moisture and mud.

9. 9

   Recalibrate hitch (Bypass)

   Recalibrate the hitch after installing the eliminator kit.