Fendt 8.1.36 – Rear EPC: A035 - Rotary switch, rear power lift, 'mixed control'

The system detects a signal fault or line interruption from the A035 mix potentiometer. Because the module cannot read the potentiometer's signal, setpoint changes for the mixed control cannot be made, and the rear power lift control performance may be restricted or locked.

• 309 Vario COM III
• 310 Vario COM III
• 311 Vario COM III
• 312 Vario COM III
• Fendt 300 Vario
• Fendt 400 Vario (COM III)
• Fendt 700 Vario (COM III)
• Fendt 800 Vario (COM III)
• Fendt 900 Vario (COM III)

1. 1

   Visually inspect the A035 rotary switch on the EHR control panel for physical damage, sticking, or liquid ingress.

2. 2

   Check the wiring harness between the A035 mix potentiometer and the Rear EPC module for line interruptions, chafing, or short circuits.

3. 3

   Back-probe the potentiometer connector to verify it outputs a smooth, linear voltage signal as the dial is turned. A drop out or open/shorted reading indicates internal failure.

4. 4

   Disconnect the EHR control panel and check for corroded, bent, or loose pins at the separation point.

1. 1

   Power Down

   Turn off the tractor ignition and disconnect the battery ground cable to prevent electrical spikes.

2. 2

   Access the Control Panel

   Carefully pry or unscrew the trim surrounding the EHR module / Variocentre console on the right-hand mudguard/armrest to access the underside of the control panel.

3. 3

   Disconnect Harness

   Unplug the electrical connector leading to the A035 rotary switch / EHR module.

4. 4

   Component Replacement

   If the A035 mix potentiometer is available as a standalone switch for your specific model, unclip it from the panel and install the new switch. If the rotary switches are integrated into the larger EHR control panel module, remove the retaining screws for the entire EHR module and replace the unit.

5. 5

   Reassembly

   Reconnect the wiring harness, ensuring the connector clicks securely into place. Reinstall the console trim.

6. 6

   Calibration & Clearing

   Reconnect the battery. Turn on the ignition, clear the stored 8.1.36 fault code via the tractor's diagnostic menu or FENDIAS tool, and test the rear power lift mixed control dial to ensure the EPC responds to setpoint changes.