Case IH 2561 – UCM: Uncommanded F2/R1 Synchronizer Neutral

The transmission system detected that the F2/R1 synchronizer physically shifted into the neutral position without a command from the transmission controller. This can be caused by a vane pump circuit pressure regulation problem, a transmission control valve issue, or a malfunction within the control module itself.

• Optum
• Puma 125
• Puma 165
• Puma 180
• Puma 185 CVX
• Puma 195
• Puma 210
• Puma 225 CVX
• T7.175
• T7.190
• T7.210
• T7.225

1. 1

   Check for related codes relating to the F2/R1 synchronizer (such as 2517, 2518 for potentiometer signal issues, or 2521-2524 for F2/R1 solenoid circuit faults).

2. 2

   Verify that the tractor battery power supply has not been connected to an external power supply. If an external power supply is connected, disconnect it and test the system for normal operation.

3. 3

   Use a diagnostic tool to check the F2/R1 synchronizer position sensor (Potentiometer X534). Expected values are F2 Position: 300 - 1200, Neutral Position: 2050 - 2800, R1 Position: 3550 - 4700.

4. 4

   Verify the vane pump circuit pressure, as a drop in pressure can cause the synchronizer to slip into neutral.

1. 1

   Inspect and replace sensor

   Check the F2/R1 synchronizer position sensor (Potentiometer X534) and its wiring harness. If the sensor is faulty or reading out of range, replace the position sensor.

2. 2

   Update UCM software

   If the sensor is functioning correctly and the fault is still present, download and flash the correct (latest) level of software to the UCM.

3. 3

   Replace UCM

   If the fault recurs after a software update and sensor verification, remove and replace the Universal Control Module (UCM).

4. 4

   Inspect and repair mechanical transmission

   If electrical and hydraulic valve controls are ruled out, open the transmission CVT housing to inspect the mechanical driveline. Inspect the F2/R1 synchronizer unit, the F2/R1 shift fork, circlips, and bolts for physical wear or breakage that would allow the synchronizer to physically jump out of gear.