Fendt A.1.35 – ECU, enhanced control (A002): Y017 - Auxiliary control valve (Spool valve fault, valve 3) Overvoltage

Overvoltage (> 45 volts) or 'High overvoltage over 45 V' at the Y017 auxiliary control valve. As a safety measure, the valve automatically moves into the neutral position and auxiliary operation for that valve is disabled.

• 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 (409, 410, 411, 412)
• Favorit 700 Vario series (711, 712, 714, 716)
• Favorit 900 Vario series (916, 920, 924, 926, 930)
• 300 Vario COM III
• 400 Vario COM III
• 700 Vario COM III
• 800 Vario COM III
• 900 Vario COM III

1. 1

   Verify the tractor's overall system voltage and alternator output to rule out a failing voltage regulator causing a system-wide overvoltage spike.

2. 2

   Check if other auxiliary valves (Y015, Y016, Y018, Y019) are throwing similar overvoltage codes to isolate the fault to Valve 3.

3. 3

   Inspect the wiring harness and Connector X328 (designated for Valve 3) for corrosion, water ingress, or a short-to-power condition.

4. 4

   Verify the integrity of the CAN bus communication lines (CAN II pin 4 and 5).

1. 1

   Safely park the tractor, relieve hydraulic pressure, and turn off the engine.

   Ensure the machine is safe to work on before beginning repairs.

2. 2

   Access the electrical valve block (VENDI) at the rear of the tractor.

   Locate Valve 3 (Y017), which is typically identified by a red decal or color-coding.

3. 3

   Disconnect connector X328 from the Y017 valve.

   Prepare the connector for voltage testing.

4. 4

   Test the supply voltage at the harness connector with the key on using a multimeter.

   It should be within the normal operating range (12V-14V). If the harness is supplying normal voltage but the valve reports >45V, the internal magnet output stage/circuit board of the spool valve has failed.

5. 5

   Remove the faulty Y017 auxiliary control valve from the hydraulic block and install the replacement valve.

   Replace the valve if internal failure is confirmed.

6. 6

   Program the new auxiliary control valve for 'position 3' using the FENDIAS diagnostic tool via the EOL (End of Line) program.

   Crucial Step: The valve will not be recognized by the bus until this calibration is complete.

7. 7

   Clear the fault codes and test the hydraulic function.

   Verify the repair was successful and the fault does not return.