Case IH 2520 (517971.07) - DEC – UCM (Universal Control Module): Synchronizer not moving towards R1

The measured synchronizer position is lower than the prefixed threshold. The transmission controller detects that the synchronizer is failing to physically engage or move toward the R1 position when commanded.

• VESTRUM CVX
• Puma 150 CVX
• Puma 165 CVX
• Puma 175 CVX
• Puma 185 CVX
• Puma 200 CVX
• Puma 220 CVX
• Puma 240 CVX
• Optum CVX
• Maxxum CVX
• T7.175 AutoCommand
• T7.190 AutoCommand
• T7.210 AutoCommand
• T7.225 AutoCommand
• T7.270 AutoCommand

1. 1

   Check for other error codes: If any other error codes are displayed, diagnose and resolve those first.

2. 2

   Attempt Calibration: If no other codes are present, perform the transmission calibration procedures (Universal controller - H1 - Calibration procedures).

3. 3

   Hydraulic Pressure Test: If it is not possible to calibrate the transmission or the fault is still present, perform a transmission hydraulic pressure test.

4. 4

   Visual Inspection: Check the R1 synchronizer solenoid connector (X-536), the wire harness connector (X-022), and the UCM connector (X-950). Ensure the connectors are fully seated, not damaged, pins are in the correct position, and the fit is tight.

1. 1

   Test the R1 Synchronizer Solenoid

   Disconnect the R1 synchronizer solenoid connector (X-536). Measure the resistance between the solenoid terminals. If the resistance indicated is not approximately 10 Ohms, the solenoid has failed internally. Remove and replace the R1 synchronizer solenoid. If the resistance is correct, proceed to Step 2.

2. 2

   Check for a Short to Ground

   Check continuity between connector X-536 pin 1 and a known good chassis ground. If a short to ground is indicated, repair or replace the transmission wire harness.

3. 3

   Check for a Short to Positive Voltage

   Disconnect the UCM controller connector X-950. Turn the ignition switch ON. Measure the voltage between connector X-536 pin 1 and ground. If voltage is indicated, repair or replace the wire harness.

4. 4

   Check for an Open Circuit

   Check continuity between the solenoid connector (X-536) and the UCM connector (X-950). If an open circuit is indicated, repair or replace the wire harness.

5. 5

   Software and UCM Replacement

   If the solenoid and wire harness test perfectly fine, download the correct/latest level of software to the UCM. If the fault recurs after a software flash, remove and replace the UCM.