Case IH 2713 (517971.17) - DEC – UCM (Unit Control Module): R1 solenoid - short to ground

The transmission control system has detected a short circuit to ground in the R1 (Reverse 1) synchronizer solenoid circuit. This means voltage intended for the solenoid is finding an unintended path to the chassis ground, preventing the R1 synchronizer from engaging properly.

• VESTRUM CVX
• Case IH Puma Series: 165, 180, 195, 210, 225 CVX
• Case IH Magnum Series: 210, 220, 225, 235, 335, 340

1. 1

   Harness Inspection: Visually inspect the transmission wire harness for chafing, melting, or pinch points that could cause a short to ground.

2. 2

   Connector Check: Disconnect and inspect the R1 synchronizer solenoid connector for corrosion, moisture, or bent pins.

3. 3

   Resistance Testing: Test the R1 solenoid for proper internal resistance to determine if the solenoid coil itself has shorted to its casing.

4. 4

   Circuit Isolation: Disconnect the harness at the UCM and at the solenoid. Check for continuity between the solenoid signal wire and the chassis ground to isolate whether the short is in the wiring or the component.

1. 1

   Repair/Replace Wiring

   If the diagnostic tests indicate a short circuit or short to ground in the wiring, repair the damaged section of the wire harness or replace the harness entirely as required.

2. 2

   Replace Solenoid

   If the wiring tests good but the R1 solenoid fails the resistance test, remove and replace the R1 synchronizer solenoid.

3. 3

   Software Update

   If the wire harness and solenoid are both functioning correctly, connect the diagnostic tool and download the correct/latest level of software to the UCM.

4. 4

   UCM Replacement

   If the fault recurs after verifying the wiring, replacing the solenoid, and updating the software, the UCM itself has an internal short. Remove and replace the UCM.

5. 5

   Clear and Test

   Once the root cause has been rectified, clear the error code from the UCM memory and test the tractor's transmission system for normal operation.