Fendt A.1.82 – A057 - ECU, steering controller (Autoguide) or A050 - ECU, basic control unit: Y099 - Solenoid valve, pilot pressure (Autoguide)

This fault code indicates an electrical issue with the pilot pressure solenoid valve for the Autoguide/VarioGuide system, specifically a short circuit in the supply line or a wiring break in the electrical supply line to the pilot pressure solenoid valve (Y099).

• 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)
• FENDT 700 Vario (COM III)
• FENDT 800 Vario (COM III)
• FENDT 820 Vario greentec (COM III)
• FENDT 900 Vario (COM III)

1. 1

   Check the electrical supply line to the Y099 pilot pressure solenoid valve for any visible breaks, chafing, or short circuits to the ground

2. 2

   Consult Wiring Diagram Sheet 39 to trace the circuit between the steering controller ECU and the Y099 valve

3. 3

   Test the Y099 solenoid valve itself for internal shorts or an open circuit using a multimeter

1. 1

   Safety First

   Ensure the tractor is turned off, the parking brake is applied, and the hydraulic system is depressurized.

2. 2

   Locate the Valve

   Locate the Y099 pilot pressure switch-off solenoid valve on the steering valve block (often designated as the Autoguide steering valve block).

3. 3

   Inspect and Repair Wiring

   Disconnect the harness at the Y099 valve. Inspect the connector pins for corrosion or damage. If a break or short is found in the wiring harness, repair the damaged section of the wire or replace the affected harness segment.

4. 4

   Replace the Solenoid Valve

   If the wiring and supply voltage test fine but the fault persists, the solenoid valve itself has likely failed internally. Remove the retaining hardware for the Y099 solenoid valve, extract the faulty valve, and install the replacement.

5. 5

   Clear Codes and Calibrate

   Reconnect the harness, clear the fault codes using the FENDIAS service diagnostics program, and perform a functional test of the Auto-Guide system to ensure the steering valve block operates correctly.