Case IH 2400 – Transmission Controller (TCM) / Gear Control Module (GCM2): Low / high range synchronizer not calibrated or bad calibration

The transmission controller has detected that the calibration values for the low/high range synchronizer are missing, out of tolerance, or invalid.

• Optum
• Puma 150
• Puma 165
• Puma 175
• Puma 190
• Puma 210
• Maxxum
• T7.175
• T7.190
• T7.210
• T6000

1. 1

   Check for related fault codes (e.g., 2417, 2418, or 2420) indicating the low/high range synchronizer potentiometer voltage is too high, too low, or out of band

2. 2

   Verify power supply by ensuring the tractor battery has not been connected to an external power supply or jump box, which can cause voltage irregularities

3. 3

   Test the high range clutch solenoid by measuring electrical resistance between terminal 1 and terminal 2 (should read between 8 and 11 Ohms)

4. 4

   Inspect the synchronizer potentiometer and its physical linkage for wear, damage, or looseness

1. 1

   Address Hardware Failures

   If the high range clutch solenoid fails the resistance test (reads outside of 8–11 Ohms), remove and replace the solenoid. If the potentiometer or linkage is physically damaged, replace those components.

2. 2

   Clear Old Data

   Access the tractor's transmission calibration menu. Perform an 'H8' operation to clear all calibration values and stored fault codes from the EEPROM, resetting them to default.

3. 3

   Recalibrate the Transmission

   Perform the Semi-Powershift transmission calibration routine directly through the tractor's in-cab control screen. Follow the on-screen prompts to teach the controller the new engagement points for the low/high range synchronizer.