Fendt A.1.D9 – ENHANCED CONTROL: Hydraulic oil level sensor — Tank is empty

The sensor monitoring the hydraulic oil reservoir has detected that the hydraulic oil tank is completely empty, or there is a complete loss of signal from the sensor mimicking an empty tank. This triggers a safety lockout where all spool valves are locked and pilot control is disabled to prevent pump damage.

• 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
• 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 Farmer 400 / 400 Vario
• Fendt Favorit 700 / 700 Vario
• Fendt Favorit 800 / 800 Vario
• Fendt Favorit 900 / 900 Vario
• 916
• 920
• 924
• 926
• 930
• 936

1. 1

   Physical Level Check: Immediately check the actual hydraulic oil level using the sight glass or dipstick. Do not run the tractor until this is verified to prevent pump damage.

2. 2

   Leak Inspection: If the tank is genuinely empty or severely low, inspect the entire hydraulic circuit, remote valves, and undercarriage for catastrophic leaks.

3. 3

   Wiring & Connector Inspection: If the tank is full, the fault is electrical. Inspect the wiring harness and the sensor connector (Separation point X214) for corrosion, backed-out pins, or wire chafing.

4. 4

   Sensor Location: Locate the hydraulic oil level sensor (S036 / B084) on the left side of the tractor, on top of the clutch housing, directly below the cab.

5. 5

   Continuity Test: Test the signal wire (Pin 22 on the yellow X101 instrument panel connector to Pin 1 on the X214 sensor connector) for continuity and check the sensor ground.

1. 1

   Top Up Fluid (If Low)

   If the tank is empty, fill it with the approved hydraulic fluid (e.g., Fendt Super Hyd, Fendt Extra Hyd 68, or STOU SAE 5W-30/10W-40 depending on your specific model's climate requirements).

2. 2

   Access the Sensor

   If the fluid level is correct but the code persists, locate the S036/B084 sensor on the left side of the clutch housing below the cab.

3. 3

   Repair Wiring

   If the diagnostic checks revealed a broken wire or corroded connector at X214, repair the harness using OEM-approved waterproof splices or replace the connector pigtail.

4. 4

   Replace the Sensor

   If the wiring is intact, the sensor itself has failed internally. Unplug the electrical connector, unthread the faulty sensor from the hydraulic tank/housing, and install the new sensor. Clean the area to prevent dirt ingress during replacement.

5. 5

   Clear Codes and Test

   Turn the ignition on. Use the tractor's terminal or the FENDIAS diagnostic tool to clear the stored A.1.D9 fault code. Verify that the spool valves are no longer locked out and operate normally.