Fendt 1E.1.26 – Engine Control Unit (ECU): Magnetic clutch, air conditioning compressor - Cable break or short circuit

The air conditioning compressor magnetic clutch cannot engage, rendering the air conditioning system non-operable.

• 309 Vario COM III
• 310 Vario COM III
• 311 Vario COM III
• 312 Vario COM III
• 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 (309, 310, 311, 312)
• Fendt 400 Vario COM III
• Fendt 700 Vario COM III
• Fendt 800 Vario COM III
• Fendt 900 Vario COM III

1. 1

   Inspect the wiring harness leading to the AC compressor (located on the left side of the engine) for obvious rubbing, melting, or severed wires.

2. 2

   Disconnect the plug at the Y024 magnetic clutch and check for corrosion, pushed-out pins, or moisture ingress.

3. 3

   Using a multimeter and the Deutz engine control circuit diagram, test the wiring between the Engine ECU and the Y024 connector for continuity, short to ground, or short to power.

4. 4

   Measure the resistance of the magnetic clutch coil itself to determine if it has failed internally (open limit or zero ohms).

1. 1

   Resolve Wiring Issues

   If a break or short is found in the harness, repair the damaged section of the wire or replace the affected pigtail connector.

2. 2

   Replace the Clutch/Compressor

   If the wiring is intact but the magnetic clutch coil is internally shorted or open, replace the magnetic clutch assembly. It is common practice to replace the entire AC compressor unit if the tractor has high hours.

3. 3

   Clear the Fault

   Connect the SERDIA diagnostic tool to the tractor.

4. 4

   Delete Error

   Navigate to the Engine ECU module and clear fault code FC:0053.

5. 5

   Verify Operation

   Start the tractor, turn on the air conditioning, and verify that the Y024 magnetic clutch engages and the system cools.