Case IH 2300 – Transmission Control Module (TCU): 19th gear solenoid - open circuit or short to ground

The Transmission Control Module (TCU) has detected an open circuit or short to ground (or short circuit with ground) in the 19th gear solenoid circuit.

• Puma/Mid Range Magnum
• Puma series (165, 180, 195, 210)
• Magnum series (180, 190, 210, 235-340)
• Maxxum series
• Steiger series

1. 1

   Locate the 19th gear solenoid on the transmission valve block (connector C290 or C268 for 50 kph models)

2. 2

   Disconnect the harness from the solenoid and the transmission controller to test harness continuity for breaks

3. 3

   Test the circuit for a short to ground or a short to power

4. 4

   Measure the resistance across the pins of the 19th gear solenoid coil using a multimeter and compare to service manual specs

5. 5

   Monitor live current to the solenoid via the diagnostic menu (H Menu) — it should read 0 when clutch is off and 70 (or 750) when commanded on

1. 1

   Inspect Wiring and Connectors

   Visually inspect the wiring harness leading to connector C290/C268. Look for chafed wires, melted insulation, or pinched lines along the transmission housing.

2. 2

   Clean the Connections

   Disconnect the solenoid and inspect the pins for corrosion, moisture, or pushed-back terminals. Clean with contact cleaner and apply dielectric grease if necessary.

3. 3

   Repair the Circuit

   If a short or open circuit is found in the harness during the diagnostic phase, repair the damaged wire or replace that section of the transmission harness.

4. 4

   Replace the Solenoid

   If the wiring tests perfectly but the solenoid coil fails the resistance test (or is internally shorted to its own casing), remove the retaining hardware for the 19th gear solenoid valve on the transmission manifold and install a new solenoid.

5. 5

   Controller Replacement (Worst Case)

   If the wiring harness is completely intact, the solenoid tests within spec, and the code persists, the transmission controller itself may have a failed internal driver and will need to be replaced and recalibrated.

6. 6

   Clear Codes and Calibrate

   After repairs are made, clear the fault codes from the EEPROM and perform a transmission clutch calibration to ensure the new solenoid engages smoothly.