Fendt 04.1.64 – A050 - ECU, basic control unit: A050 - ECU, basic control unit; Y004 - Solenoid valve, turbo-clutch

This code indicates a PWM (Pulse Width Modulation) actuation fault with the turbo-clutch solenoid valve (Y004). The system detects that the solenoid valve actuation is faulty, which can mean the pressure does not drop when the TK (turbo-clutch) valve is opened, or there is an electrical short/open circuit.

• 309 Vario COM III
• 310 Vario COM III
• 311 Vario COM III
• 312 Vario COM III
• 922 Vario COM III
• 924 Vario COM III
• 927 Vario COM III
• 930 Vario COM III
• 933 Vario COM III
• 936 Vario COM III
• Fendt 300 Vario (COM III)
• Fendt 400 Vario (COM III) / Farmer 400
• Fendt 700 Vario (COM III) / Favorit 700 / 700 SCR
• Fendt 800 Vario (COM III)
• Fendt 900 Vario (COM III) / Favorit 900 / 900 SCR (e.g., 916, 922, 924, 927, 930, 933, 936)

1. 1

   Check fuse F56, as a blown fuse will cause a turbo-clutch solenoid valve actuation fault

2. 2

   Inspect the wiring harness between the A050 ECU and the Y004 solenoid valve, specifically checking separation point X317 for corrosion, moisture, or backed-out pins

3. 3

   Test the Y004 solenoid valve for an internal short circuit or abnormal power consumption

4. 4

   Check if the high-pressure valves are opening properly depending on engine speed, verifying hydraulic pressure if the electrical circuit is intact

1. 1

   Secure the Machine

   Park the tractor on a level surface, engage the parking brake, and turn off the ignition.

2. 2

   Verify Power Supply

   Locate the fuse panel and test fuse F56. Replace it if blown, but be prepared to trace a short if the new fuse blows immediately.

3. 3

   Access the Valve

   Locate the Y004 Solenoid valve. On many Vario models, the Y004 valve is located on the right side of the transmission. You may need to remove the right rear wheel and the side panel to gain clear access.

4. 4

   Test the Circuit

   Disconnect the X317 connector at the Y004 valve. Use a multimeter to check for continuity back to the A050 ECU and ensure there is no short to ground.

5. 5

   Replace the Valve

   If the wiring is good but the solenoid coil fails a resistance test (or is internally shorted), remove the retaining hardware and extract the Y004 solenoid valve from the transmission block. Install the new OEM replacement valve and lubricate the O-rings with clean transmission oil (STOU 10W-40).

6. 6

   Calibrate the Transmission

   After replacing the Y004 valve, you must perform a transmission calibration using the tractor's terminal or FENDIAS diagnostic software. The specific calibration code for the Y004 Solenoid valve (turbo-clutch) is 4009.