Fendt 4.1.E0 – A002 - ECU, enhanced control: Y004 - Solenoid valve, turbo-clutch — Wrong characteristic stored

The transmission control system has detected that the calibration values (characteristics) for the turbo-clutch solenoid valve (Y004) are either missing, drifted, or incorrect.

• 409 Vario
• 410 Vario
• 411 Vario
• 412 Vario
• 711 Vario
• 712 Vario
• 714 Vario
• 715 Vario
• 716 Vario
• 717 Vario
• 718 Vario
• 916 Vario
• 920 Vario
• 924 Vario
• 926 Vario
• 930 Vario
• Fendt Farmer 400 series
• Fendt Favorit 700 and 900 series
• Fendt 300, 400, 700, 800, and 900 Vario series (including COM III and S4 generations)

1. 1

   Verify the wiring harness and connectors going to the Y004 solenoid valve for a PWM-supply failure, short circuits, or a fault on the earth side.

2. 2

   Ensure the Y004 valve is not physically jammed, which would prevent pressure from dropping when the TK valve is opened.

3. 3

   Check the transmission oil supply and pressure, including the filter contamination pressure switch (S017), to ensure the pressure filter is not clogged and causing oil starvation.

1. 1

   Connect diagnostic tool

   Connect the FENDIAS diagnostic tool (or access the onboard terminal calibration menu if supported on your specific model).

2. 2

   Initiate EOL reprogramming

   Initiate the End-Of-Line (EOL) reprogramming / calibration procedure for the transmission.

3. 3

   Run Calibration Code 4009

   Run Calibration Code "4009" (Turboclutch function calibration). This will relearn and store the correct characteristics for the Y004 solenoid valve.

4. 4

   Test drive the tractor

   Test drive the tractor. If the calibration fails to hold, or if the code immediately returns alongside electrical fault codes, the Y004 solenoid valve is likely suffering from internal electrical drift or mechanical sticking and must be replaced.

5. 5

   Replace Y004 solenoid valve

   If replacement is necessary, safely relieve hydraulic pressure, swap the Y004 solenoid valve on the transmission control block, top up any lost transmission fluid (e.g., STOU SAE 10W-40 or 15W-40), and repeat Calibration Code 4009.