Fendt 9.3.28 – EPC C: Quick lift switch, front — Fault in front EPC quick lift switch

The system has detected an electrical fault (signal out of range) in the front Electronic Power Control (EPC) quick lift switch. The fault code is triggered if the signal voltage drops below 1.6 VDC or exceeds 6.8 VDC. The control is terminated and locked up. The front power lift 'Raise' and 'Lower' functions are disabled from the cab and are only possible via the external buttons.

• 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
• Fendt 300 Vario (COM III, S4)
• Fendt 400 Vario (COM III)
• Fendt 700 Vario (COM III, S4)
• Fendt 800 Vario (COM III, S4)
• Fendt 900 Vario (COM III, S4)

1. 1

   Turn the ignition ON and ensure the engine is running.

2. 2

   Unlock the EPC on the quick lift switch.

3. 3

   Set the lift height limiter to maximum.

4. 4

   Test the Floating Position: Set the depth control to Position 10 (floating position). The expected signal should be approximately 3.8 VDC (18 mADC).

5. 5

   Test the Transport Position: Switch the quick lift switch to lower ("control") and set the depth control to Position 0 (transport position). The expected signal should be approximately 0.7 VDC (3.5 mADC).

6. 6

   Check External Buttons: Test the external front power lift "raise" button (S021). Check Earth pin 45 / X1403; the signal should toggle between 6.1 VDC and 0 VDC.

7. 7

   Evaluate Thresholds: If the quick lift switch signal is reading below 1.6 VDC or above 6.8 VDC, the switch has failed or there is a short/open in the wiring harness.

1. 1

   Inspect Wiring

   Trace the wiring harness from the front EPC quick lift switch (located on the power lift control module/armrest) to the EPC C module. Look for pinched wires, corrosion at the separation points, or loose connector pins.

2. 2

   Test the Switch

   Perform the voltage diagnostic checks listed in the things to check section using a multimeter.

3. 3

   Replace the Component

   If the wiring is intact but the switch voltages are outside the 1.6 VDC – 6.8 VDC threshold, the switch/module has failed internally and must be replaced.

4. 4

   Clear Fault Codes

   Once repaired, clear the fault code from the tractor's memory. On many Vario models, this can be done by simultaneously pressing keys D, B, and C on the terminal, or by pressing and holding the designated return key until the code clears.

5. 5

   Recalibrate the EPC

   After replacing EPC components, you must perform a system calibration. Use the tractor's terminal or FENDIAS adapter box to run Calibration 9001 (front EPC - depth control) and Calibration 9002 (front EPC - position control).