Case IH 2403 – TCU: Range Shift Synchronizer Engagement Failure

This fault indicates a mechanical or electrical failure preventing the transmission's range shift synchronizer from properly engaging during a gear or shuttle shift. It is specifically flagged on machines equipped with Semi-Powershift (SPS) transmissions and is commonly caused by a faulty high range clutch solenoid, wiring issues, or low voltage.

• Optum
• Puma Series
• Maxxum Series
• Steiger Series
• MXM / TM Series

1. 1

   Test the High Range Clutch Solenoid: Disconnect the solenoid and measure the resistance between terminal 1 and terminal 2. The resistance must be between 8 to 11 Ohms.

2. 2

   Check for Electrical Shorts: If the solenoid tests okay, check the wiring harness for a short to positive voltage or ground. Disconnect the UCM connector (e.g., X-950) and measure voltage between connector pins (e.g., X-643 pin 1 and ground; X-643 pin 2 and ground).

3. 3

   Verify Power Supply: Check for a faulty charging system or external power supply issues, as low battery voltage can prevent clutch solenoids from operating correctly.

4. 4

   Inspect the CCU: Verify that the Central Control Unit (CCU) is functioning properly and not suffering from an internal hardware error.

1. 1

   Prep the machine

   Park the tractor on a level surface, engage the parking brake, turn off the engine, and disconnect the battery to prevent electrical shorts.

2. 2

   Locate the solenoid

   Locate the transmission control solenoids. Depending on the specific model, the high range clutch solenoid is typically located in the bell housing or inside the transmission side cover.

3. 3

   Remove the faulty solenoid

   Disconnect the electrical wiring harness connector from the solenoid. Remove the retaining bolts or clips holding the solenoid valve in the transmission block.

4. 4

   Install the new solenoid

   Lubricate the O-rings on the new solenoid with clean transmission fluid. Insert the new solenoid into the valve body and secure it with the retaining hardware.

5. 5

   Reconnect and reassemble

   Reconnect the electrical harness to the new solenoid. Replace any transmission covers that were removed.

6. 6

   Calibrate the transmission

   Reconnect the battery. Clear the stored fault codes using a diagnostic tool. You must perform a transmission calibration procedure (clutch calibration) to ensure the TCU learns the engagement points of the new solenoid.