Case IH 2324 – Transmission Control Module (TCU): Transmission mid speed sensor - short to ground

The controller is detecting that the signal circuit for the transmission's mid-speed sensor is shorted directly to a ground source, resulting in a loss of valid speed data from that sensor.

• Puma/Mid Range Magnum
• Case IH Puma Series (125, 130, 140, 145, 160, 170, 185, 200, 210, 215, 230, CVX models)
• Case IH Magnum Series (235, 260, 290, 315, 340, 370, MX210, MX230, MX255, MX285)
• Case IH Maxxum / MXM Series (120, 130, 140, 155, 175, 190)
• Case IH Farmall Series (40, 45, 50 with Cab/CVT)

1. 1

   Inspect the transmission mid-speed sensor and its wiring harness for physical damage, rubbing, or melted insulation that could cause a short to the chassis.

2. 2

   Disconnect the mid-speed sensor and check the pins on both the sensor side and the harness side for corrosion, moisture, or bent pins.

3. 3

   With the sensor and battery disconnected, use a multimeter to test the signal wire from the sensor connector back to the Transmission Controller for continuity to ground. Continuity indicates a shorted harness.

4. 4

   If the harness tests fine (no short to ground), the internal circuitry of the mid-speed sensor itself has likely failed and shorted internally.

1. 1

   Disconnect Power

   Disconnect the tractor's battery to prevent electrical spikes during repair.

2. 2

   Access the Sensor

   Locate the transmission mid-speed sensor on the transmission housing (refer to the specific model's service manual for exact placement, often near the mid-range clutch manifold).

3. 3

   Repair or Replace

   If the harness is damaged: Repair the shorted section of the wiring harness using appropriate weatherproof splices, or replace the harness section. If the sensor is faulty: Unbolt and remove the old mid-speed sensor. Clean the mating surface on the transmission case. Install the new sensor and torque to OEM specifications.

4. 4

   Reconnect

   Plug the sensor connector back into the harness and reconnect the battery.

5. 5

   Clear Codes

   Use the tractor's H-Menu (specifically the H8 or HC operation menu) or an Electronic Service Tool (EST) to clear the stored 2324 fault code from the EEPROM.

6. 6

   Recalibrate

   Depending on the model, you may need to perform a transmission calibration procedure after replacing speed sensors to ensure smooth shifting.