Fendt 4.1.65 – Transmission Control Module (A050 - ECU, basic control unit): Actuation fault on earth side of Y053 Active hold function solenoid valve

The system detects that the actuation of the earth (ground) side of the Y053 solenoid valve is faulty. The tractor will have no active hold/parking function, which affects the engine brake stationary control.

• 411 Vario COM III
• 412 Vario COM III
• 413 Vario COM III
• 414 Vario COM III
• 415 Vario COM III
• 712 Vario COM III
• 714 Vario COM III
• 716 Vario COM III
• 718 Vario COM III
• 818 Vario COM III
• 820 Vario COM III
• Fendt 300 Vario (COM III)
• Fendt 400 Vario (COM III) / Farmer 400
• Fendt 700 Vario (COM III) / Favorit 700
• Fendt 800 Vario (COM III)
• Fendt 900 Vario (COM II, COM III) / Favorit 900

1. 1

   Inspect the earth/ground circuit wiring harness between the Transmission ECU (A050) and the Y053 valve for open circuits, corrosion, or a short to ground.

2. 2

   Verify the integrity of the signal transmission line to the Y053 valve.

3. 3

   Test the K051 active hold function relay contacts and operation to rule out relay failure.

1. 1

   Access the Valve

   The Y053 Active hold function solenoid valve is typically located on the right side of the transmission. You may need to detach the right rear wheel and panel to gain clear access.

2. 2

   Verify Wiring

   Disconnect the harness at the Y053 solenoid and the A050 ECU. Perform a continuity test on the earth-side wire. Repair any breaks or chafed wires in the harness.

3. 3

   Test/Replace Relay

   Locate relay K051 in the electrical panel. Swap it with a known good relay of the same type to see if the active hold function returns.

4. 4

   Replace the Solenoid Valve

   If the wiring is intact and the relay is functioning, the Y053 solenoid valve itself has failed internally and must be replaced.

5. 5

   Clear Codes

   Reconnect all components, turn on the tractor, and use the terminal/FENDIAS system to clear the stored 4.1.65 fault code. Test the active hold function to ensure the repair was successful.