Case IH 2064 – Transmission Controller (TRANS / UCM): Reverse synchroniser did not engage

The transmission controller commanded the reverse synchronizer to engage, but the feedback sensor (potentiometer) did not detect the synchronizer physically moving into the correct reverse position within the expected timeframe.

• Maxxum
• Puma series (140, 165, 180, 195, 210, 225, 260 CVX)
• MX Magnum
• MXM series (MXM120, MXM130, MXM140)
• Farmall series (60-115U/C)
• Steiger
• CX series

1. 1

   Check for related electrical codes (2061, 2062, 2066, 2068) that point to a specific electrical failure

2. 2

   Inspect the transmission wiring harness at the transmission control valve block for damaged wires, corrosion, or loose pins at the reverse synchronizer solenoid and potentiometer

3. 3

   Test the resistance of the reverse synchronizer solenoid coil and verify the voltage sweep of the synchronizer potentiometer

4. 4

   Ensure transmission oil is at operating temperature (at least 60°C) and use the onboard diagnostic menu (H3) to test hydraulic pressure and attempt a manual calibration

1. 1

   Resolve Electrical Faults

   If related codes (2066, 2068, 2061, 2062) are present, repair the wiring harness or replace the faulty electrical component (solenoid or potentiometer) on the exterior of the transmission valve block.

2. 2

   Replace Solenoid/Sensor

   If the wiring is intact but the solenoid fails a resistance test or the potentiometer has a dead spot, replace the defective sensor/valve.

3. 3

   Internal Mechanical Repair

   If the electrical circuits, solenoids, and potentiometers are functioning correctly and hydraulic pressure is verified, the fault is internal. Split the tractor and disassemble the transmission to replace the forward/reverse synchronizer assembly.

4. 4

   Recalibrate

   After any repair (whether electrical or mechanical), perform a full transmission calibration using the tractor's onboard diagnostic system so the controller can relearn the engaged/disengaged positions of the synchronizer.