Fendt 05.1.9A – Basic Control Unit (ECU A050): S026 - Switch, steering pump flow controller

This code indicates a plausibility error with the steering pump flow monitor. Specifically, the system detects a switch fault where the switch does not close or remains open even when there is no oil flow.

• 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 400 Vario (409, 410, 411, 412, 413, 414, 415)
• Fendt 500 Vario (512, 513, 514, 516)
• Fendt 700 Vario / Favorit 700 (711, 712, 714, 716, 718, 720, 722, 724)
• Fendt 800 Vario (815, 817, 818, 820, 822, 824, 826, 828)
• Fendt 900 Vario / Favorit 900 (916, 918, 920, 922, 924, 927, 930, 933, 936, 939)

1. 1

   With the engine turned OFF, use a multimeter to check the voltage at the S026 switch. The reading must be < 1.1 V (or check for a closed circuit depending on the specific model year).

2. 2

   Locate separation point X236 (the connector for the S026 switch) on the right side of the tractor at the central valve block.

3. 3

   Inspect the signal line to the flow monitor for any open circuits, short circuits to earth, or corrosion.

1. 1

   Preparation

   Turn off the tractor, remove the key, and ensure the hydraulic system is depressurized.

2. 2

   Access the Switch

   Navigate to the right side of the tractor and remove the protective cover over the central valve block to expose the hydraulic control valves and sensors.

3. 3

   Disconnect Wiring

   Carefully disconnect the X236 electrical connector from the S026 steering pump flow controller switch.

4. 4

   Remove the Faulty Sensor

   Unthread the faulty sensor/filter assembly from the hydraulic block. Have shop towels ready to catch residual hydraulic fluid.

5. 5

   Install the New Sensor

   Thread the new OEM flow sensor (and filter assembly, if applicable) into the central valve block. Torque to the manufacturer's specifications.

6. 6

   Reconnect and Reassemble

   Reconnect the X236 electrical connector. Reinstall the central valve block cover.

7. 7

   Clear Codes and Test

   Turn the ignition ON. The fault code should not reappear after the initial 8-second check. Start the engine and verify proper steering and hydraulic function without flow reduction.