Fendt 6.1.42 – Tractor Management System (TMS) / Central E-box: S020 - Switch (external), rear right PTO

The right external 'Rear PTO ON / OFF' pushbutton (located on the mudguard/taillamp) has been pressed for more than 30 seconds, or there is a mechanical/electrical fault (such as a short circuit, signal fault, or plausibility error) in the key. As a result, the PTO disengages, speed selection moves to neutral, and the PTO cannot be engaged normally.

• 411 Vario COM III
• 412 Vario COM III
• 413 Vario COM III
• 414 Vario COM III
• 415 Vario COM III
• 712 Vario COM III
• 714 Vario COM III
• 716 Vario COM III
• 718 Vario COM III
• 818 Vario COM III
• 820 Vario COM III
• 300 Vario Series (COM III)
• 400 Vario Series (409, 410, 411, 412)
• 700 Vario Series (711, 712, 714, 716)
• 800 Vario Series (815, 817, 818, S4)
• 900 Vario Series (916, 920, 924, 926, 930, S4)
• Katana 65 Forage Harvesters

1. 1

   Check the S020 switch on the right rear mudguard/taillamp to ensure the yellow button is not physically jammed or stuck in the depressed position by dirt or debris.

2. 2

   Attempt to engage the PTO from inside the cab using the emergency key (must be kept pressed for at least 5 seconds) to confirm the PTO clutch and internal systems are still functional.

3. 3

   Inspect separation point X230 (the electrical connector for the S020 switch) for moisture ingress, corrosion, or damaged wires that could be causing a short circuit.

4. 4

   Use a multimeter to test the switch for continuity. It should have an open circuit when resting and only close the circuit when pressed. If it shows continuity without being pressed, the switch has failed internally.

1. 1

   Disconnect Power

   Disconnect the tractor's battery to prevent electrical shorts during the repair.

2. 2

   Locate the Switch

   Locate the S020 external PTO switch on the right rear taillamp or mudguard assembly.

3. 3

   Disconnect Wiring

   Reach behind the panel and disconnect the X230 separation point connector (typically a 3-pin AMP Superseal plug) from the back of the switch.

4. 4

   Remove the Switch

   Squeeze the retaining tabs or remove the locking nut on the back of the switch to push it out of its 30mm mounting hole.

5. 5

   Install the New Part

   Insert the new switch into the mounting hole until it clicks or locks into place. Ensure the dustproof/splashproof rubber seal is seated correctly against the mudguard to prevent future water ingress.

6. 6

   Reconnect and Test

   Reconnect the X230 wiring harness plug. Reconnect the battery. Clear the fault codes from the terminal and test the PTO engagement from both the cab and the newly installed external switch.