Case IH 2660 – ZTC: Range clutch K4 shorted to power

The electrical circuit for the Range clutch K4 is shorted to power, meaning the transmission controller is detecting voltage on the K4 clutch solenoid circuit when it should not be present.

• Steiger T4B
• Steiger CVT
• Magnum CVT
• Puma CVX series

1. 1

   Disconnect the battery terminals (negative first) before working on the electrical systems or transmission control units.

2. 2

   Trace the wiring harness from the ZTC controller to the transmission solenoid valve block. Look for pinched wires, melted insulation, or areas where the wire might be shorting to a 12V power source.

3. 3

   Disconnect the K4 solenoid connector and test the resistance of the solenoid coil.

4. 4

   Check for continuity between the solenoid power pin and the battery positive terminal to isolate the short.

5. 5

   Inspect the pins on the ZTC module for corrosion or bent pins that could be bridging power to the K4 circuit.

1. 1

   Park the tractor on a level surface, turn off the engine, and disconnect the battery.

2. 2

   Clean the area around the transmission valve block to prevent dirt from entering the hydraulic system.

3. 3

   Locate the transmission solenoid valve block on the side of the CVT.

4. 4

   Undo the retaining screws and remove the protective cover.

5. 5

   Mark or tag the electrical plugs for the solenoid valves before disassembling to ensure they are reconnected to the correct clutches (e.g., K1, K2, K3, K4).

6. 6

   Disconnect the electrical connector for the K4 solenoid.

7. 7

   Remove the coil and the valve body from the transmission housing.

8. 8

   Lubricate the O-rings on the new solenoid valve with clean transmission fluid.

9. 9

   Install the new K4 solenoid valve and tighten to the specified torque.

10. 10

    Reconnect the electrical plug, reinstall the cover, and reconnect the battery.

11. 11

    Clear the fault codes from the ZTC module and test drive the tractor to ensure the transmission shifts through the K4 range smoothly.