Fendt A.1.43 – ECU, enhanced control, electric auxiliary control valves: Supply voltage > 18 volts (Voltage in excess of 18 V)

The system detects an overvoltage condition at the valve. As a safety measure, the valve automatically moves into the neutral position and locks out operation.

• 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
• 300 Vario
• Farmer 409
• Farmer 410
• Farmer 411
• Farmer 412
• Favorit 711
• Favorit 712
• Favorit 714
• Favorit 716
• Favorit 815
• Favorit 817
• Favorit 818
• Favorit 916
• Favorit 920
• Favorit 924
• Favorit 926
• Favorit 930

1. 1

   Test the supply voltage at the connector for Valve 4 (Y018) to verify if it is genuinely receiving more than 18 volts.

2. 2

   Inspect the wiring harness running to Valve 4 for chafing, melting, or damage that could cause a short to a higher voltage source.

3. 3

   Check the tractor's charging system (alternator and voltage regulator) to ensure it is not overcharging the entire system.

4. 4

   Verify the voltage supply for the CAN bus on printed circuit board A013, specifically checking fuses F040 and F041.

5. 5

   Do not swap electrical plugs between different spool valves for testing, as each plug is programmed for its specific function.

1. 1

   Isolate the Fault

   If your multimeter shows a normal operating voltage (e.g., 12V-14V) at the Y018 connector, but the tractor's diagnostic terminal still throws the A.1.43 (>18V) code, the internal electronics within the spool valve itself have failed.

2. 2

   Replace the Valve

   The microchip and circuit card are integrated into the spool valve and cannot be purchased or replaced separately. You must replace the entire auxiliary control valve assembly.

3. 3

   Clear Codes

   After installing the new valve, use the tractor's terminal to navigate to the fault codes menu (0000 - OVERALL SYSTEM/TRACTOR). Confirm, call up, and delete the fault code.

4. 4

   Recalibrate

   The new valve will need to be recognized by the CAN bus system. Depending on the exact model year, EOL (End of Line) reprogramming or a Variotronic TI teach-in may be required via the dealer diagnostic tool (FENDIAS).