Case IH U83 – Transmission Control Module (TCM) or GCM2: Synchronizer Potentiometer Connectors Swapped

The transmission controller has detected that the electrical wiring harness connectors for the transmission's synchronizer potentiometers have been plugged into the wrong sensors (interchanged). In specific 24x24 transmissions, this can alternatively indicate that the 4-5 synchroniser did not shift to 4 for calibration of the flywheel torque sensor.

• MXM
• MXM Series
• MXM 120
• MXM 130
• MXM 140
• MXM 155
• MXM 175
• MXM 190
• Puma

1. 1

   Inspect the wiring harness routing on the side of the transmission for crossed connections at the synchronizer potentiometers (wiring swap cause)

2. 2

   If the connectors are routed correctly (mechanical/hydraulic cause), check for a sticky synchronizer

3. 3

   Verify the solenoid connections

4. 4

   Test the vehicle's hydraulic pressure to ensure the synchronizer is receiving enough pressure to shift

1. 1

   Swap Connectors

   Disconnect the interchanged wiring connectors at the synchronizer potentiometers and re-connect them to their correct respective sensors.

2. 2

   Clear the Code

   Once the connectors are assembled correctly, clear the error code from the TCM.

3. 3

   Test Operation

   Start the tractor and test the transmission for normal forward/reverse and range shifting operation.

4. 4

   Recalibrate

   If shifting is harsh or the controller requires it, perform a transmission synchronizer calibration procedure (often accessed via the H-Menu on MXM models).