Case IH 2714 (517971.04) - DEC – Transmission Control Unit (TCU) / UCM / CCU: R1 Solenoid Short to Ground

The fault code indicates a short to ground (or open circuit) in the R1 (Reverse 1 or Range 1) solenoid circuit. The transmission controller detects that the electrical current/voltage for the R1 solenoid is grounding out before completing its intended circuit, which will typically prevent the synchronizer from moving towards the R1 position or cause a neutral state.

• VESTRUM CVX
• Case IH Puma series (140, 150, 165, 175, 180, 195, 210, 225 CVX / CVXDrive)
• Case IH Maxxum series (115-150 HP models)

1. 1

   Check the power supply to verify that no incorrect external power supply is connected and that the tractor's charging system is functioning properly

2. 2

   Inspect the transmission wire harness (specifically electrical schematic sheets 15 and 16 for the transmission control unit) for chafing, pinched wires, or bare spots causing a short to ground

3. 3

   Test the internal resistance of the R1 solenoid to determine if the short is internal to the solenoid coil

4. 4

   Verify the UCM software level if the wire harness and solenoid test okay

1. 1

   Disconnect Power

   Disconnect the tractor's battery to prevent electrical spikes during repair.

2. 2

   Access the Transmission Valve Block

   Locate the R1 solenoid on the transmission control valve block.

3. 3

   Harness Repair

   If a short circuit or short to ground was indicated during diagnostics, repair the damaged section of the wire harness or replace the harness entirely as required.

4. 4

   Replace the Solenoid

   If the R1 solenoid failed the resistance test (internal short), remove its retaining hardware, extract the faulty solenoid, and install a new OEM solenoid.

5. 5

   Software Flash

   If the physical wiring and solenoid are intact, connect the dealer diagnostic tool and download the correct level of software to the UCM.

6. 6

   Module Replacement

   If the wire harness is okay, the software is updated, and the fault still recurs, remove and replace the UCM (Central Control Unit).

7. 7

   Calibration

   Clear the fault codes and perform a transmission calibration to ensure the F2/R1 synchronizers engage properly.