Fendt 08.1.40 – Rear EPC (Electrohydraulic Power Control) control module (A005 or A014): S029 - Switch (external), raise rear power lift, left

Indicates a signal line fault, a key fault, or a generally faulty push-button on the external left-hand rear fender used to raise the rear power lift. The system detects an implausible signal (open circuit, short circuit, or stuck button), which locks out the external left raise button until the next trouble-free cold start. The rear power lift can typically still be operated internally from the cab.

• 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 200 V/F/P Vario series
• Fendt 300 Vario (COM III)
• Fendt 400 Vario (COM III) / Farmer 400
• Fendt 700 Vario (COM III, SCR) / Favorit 700
• Fendt 800 Vario (COM III)
• Fendt 900 Vario (COM III, SCR, S4) / Favorit 900
• Fendt Katana 85 Forage Harvesters

1. 1

   Test internal operation of the rear power lift from the cab to isolate the issue to the external S029 switch circuit

2. 2

   Inspect the S029 switch on the left rear fender for physical damage, sticking (button pressed in and not returning), or heavy dirt/water ingress

3. 3

   Disconnect the switch and inspect the wiring harness and connector for corrosion, moisture, or broken wires

4. 4

   Clear fault codes and perform a cold start reset (turn ignition off completely, wait, and turn back on) to see if the fault is hard-set or intermittent

1. 1

   Power Down

   Turn off the tractor ignition and disconnect the battery to prevent short circuits while working on the EPC system.

2. 2

   Access the Switch

   Locate the S029 'Raise' switch on the left rear fender housing.

3. 3

   Remove the Switch

   Carefully pry or unclip the faulty switch from its mounting hole in the fender.

4. 4

   Disconnect the Harness

   Unplug the electrical connector from the back of the switch.

5. 5

   Test the Circuit

   Use a multimeter to test the switch for continuity when pressed. If the switch tests fine, use the wiring diagram (Sheet 7 or Sheet 25 for Rear EPC External Buttons, depending on the model) to trace the signal line back to the Rear EPC control module for breaks.

6. 6

   Install the New Part

   Connect the tractor's wiring harness to the new OEM replacement switch.

7. 7

   Mount the Switch

   Snap the new switch securely back into the fender housing.

8. 8

   Test Operation

   Reconnect the battery, perform a cold start to reset the EPC module, and test the external left raise button to ensure the power lift actuates and the 08.1.40 code does not return.