Fendt 04.1.68 – A050 - ECU, basic control unit: Faulty residual current, high to low side brake stationary function

The system has detected that an external power source is present on the earth (low) side of the solenoid valve circuit.

• 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 300 Vario (COM III)
• Fendt 400 Vario (COM III)
• Fendt 700 Vario (COM III)
• Fendt 800 Vario (COM III)
• Fendt 900 Vario (COM III)
• 916
• 919
• 922
• 924
• 927
• 930
• 933
• 936

1. 1

   Check for shorts to power by using a multimeter to test the earth/ground wire of the Y053 solenoid valve for unwanted voltage.

2. 2

   Inspect the wiring harness from the Y053 solenoid valve back to the A050 ECU for chafed wires, melted insulation, or pinched harnesses that could bridge a live power wire to the valve's ground circuit.

3. 3

   Review OEM circuit diagrams (specifically Sheet 6) to identify the exact pinouts on the A050 ECU and the Y053 valve.

4. 4

   Disconnect the Y053 valve and check if the fault state changes. Measure the internal resistance of the solenoid coil to ensure it hasn't failed internally and shorted.

1. 1

   Locate the Valve

   The Y053 Active hold function solenoid valve is located on the right side of the transmission.

2. 2

   Gain Access

   Safely support the tractor and detach the right rear wheel and the corresponding side panel to access the transmission control valves.

3. 3

   Disconnect Electrical Connection

   Unplug the wiring harness connector from the Y053 solenoid valve.

4. 4

   Remove the Valve

   Clean the area around the valve to prevent dirt from entering the transmission hydraulic system. Unbolt and remove the faulty Y053 solenoid valve.

5. 5

   Install the New Valve

   Lubricate the O-rings on the new solenoid valve with clean hydraulic/transmission fluid. Seat the valve into the transmission block and torque the mounting bolts to OEM specifications.

6. 6

   Reconnect and Reassemble

   Reconnect the electrical harness. Reinstall the side panel and the right rear wheel.

7. 7

   Clear Codes and Test

   Turn on the ignition, clear the stored 04.1.68 fault code from the A050 ECU memory, and test the active hold/parking brake function to ensure the code does not return.