Fendt A.1.33 – Basic Control Unit (ECU A050 / E-Box): Y017 - Auxiliary control valve (Spool valve 3): Supply voltage > 18 volts.

The system has detected an overvoltage condition (exceeding 18V) at the third auxiliary hydraulic control valve (designated as component Y017). As a built-in safety mechanism, the valve's internal electronics force the main piston to move into the neutral position and lock out to prevent uncontrolled hydraulic movements.

• 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
• Farmer 400 Vario series
• Favorit 700 Vario series
• Favorit 900 Vario series
• 800 Vario series
• 900 Vario COM III series

1. 1

   Check System Voltage: Start the tractor and measure the voltage at the battery. If the alternator's voltage regulator has failed, it may be overcharging the entire system (spiking above 18V).

2. 2

   Inspect the Wiring Harness: Locate the Y017 valve (Valve 3) on the central hydraulic control block. Disconnect its specific electrical connector, designated as X328.

3. 3

   Test Connector X328: With the tractor on, measure the supply voltage at the harness side of connector X328. If it reads > 18V while the rest of the tractor is at a normal 12-14V, there is a short to a higher voltage source in the wiring harness between the E-Box and the valve.

4. 4

   Internal Valve Failure: If the harness delivers a normal 12-14V to the connector, but the code persists, the voltage-monitoring electronics inside the Y017 valve have failed, necessitating valve replacement.

1. 1

   Depressurize the System

   Turn off the tractor, lower all hydraulic implements to the ground, and relieve residual hydraulic pressure by cycling the hydraulic controls.

2. 2

   Access the Valve Block

   Locate the Y017 valve, typically the 1st control valve located on the underside of the central control block. On some models (like the Favorit 900), you may need to unscrew the right step and pull the right auxiliary tank outwards to gain clear access.

3. 3

   Disconnect Electricals

   Unplug connector X328 from the Y017 valve.

4. 4

   Remove the Valve

   Unbolt the Y017 spool valve from the hydraulic manifold block. Be prepared to catch residual hydraulic oil.

5. 5

   Install the New Valve

   Mount the replacement auxiliary control valve, ensuring all O-rings and mating surfaces are clean and properly seated. Torque the mounting bolts to OEM specifications.

6. 6

   Reconnect and Reassemble

   Plug connector X328 back in and reassemble any steps or tanks removed for access.

7. 7

   Software Calibration

   Use the FENDIAS diagnostic tool to perform an EOL (End of Line) programming/teach-in procedure so the tractor's E-Box registers the new valve's position.