Case IH 2064 – Transmission Control Unit (TCU) / Transmission Controller: Synchro not moving to reverse / Clutch C Solenoid Open Circuit or Short to Ground

Note: Code 2064 typically refers to 'Synchro not moving to reverse'. The dossier specifically addresses fault code 2065, which indicates that the transmission controller has detected an electrical fault in the circuit that powers the Clutch C solenoid valve. The circuit is either open (broken wire, disconnected plug, or burnt-out solenoid coil) or shorted to ground (bare wire touching the chassis). Because of this electrical failure, the solenoid cannot be energized, preventing Clutch C from engaging properly inside the transmission.

• Farmall
• Case IH MXM Series (MXM 120, 130, 140, 155, 175, 190)
• Case IH Puma Series
• Case IH Farmall U Pro EP Series (95U, 105U, 115U Pro EP)

1. 1

   Visual Inspection: Check the wiring harness between the TCU and the transmission external controls manifold for breaks, chafing, or pinched wires.

2. 2

   Connector Check: Inspect the electrical connector at the Clutch C solenoid for corrosion, bent pins, or moisture.

3. 3

   Electrical Testing: Use a multimeter to measure the resistance of the Clutch C solenoid coil to verify it is not internally open or shorted to ground. According to calibration data, a healthy circuit should show 0 current when off and approximately 750 mA when the solenoid is commanded on.

4. 4

   Harness Testing: Check for a short to ground in the wiring harness between the solenoid plug and the TCU.

1. 1

   Safely park the tractor, turn off the engine, and disconnect the battery

   to prevent electrical spikes.

2. 2

   Locate the transmission external controls manifold

   on the side of the transmission housing.

3. 3

   Identify the Clutch C solenoid valve

   it is grouped on the valve block alongside the Clutch A, B, D, and E solenoids.

4. 4

   Disconnect the electrical connector from the Clutch C solenoid.

5. 5

   If the wiring harness is damaged, repair or replace the affected section.

6. 6

   If the solenoid coil tests faulty, remove the retaining nut or bolt securing the solenoid coil to the valve stem.

7. 7

   Slide the old coil off.

   If the entire valve cartridge is faulty or leaking, unscrew the valve from the manifold (be prepared to catch a small amount of hydraulic oil and replace the O-rings).

8. 8

   Install the new solenoid coil or valve assembly and tighten to the OEM specified torque.

9. 9

   Reconnect the electrical connector and the battery.

10. 10

    Clear the fault codes and perform a transmission calibration

    (specifically the Clutch C filling time calibration) to ensure the TCU learns the engagement characteristics of the new solenoid.