Fendt 06.1.B7 – Multifunction Armrest (MFA) module: Communication fault with the rear PTO speed selector button

The tractor's main control unit is failing to receive the expected electrical signal or data message from the 750 rpm (540E rpm) rear PTO speed selector button on the armrest.

• 922 Vario COM III
• 924 Vario COM III
• 927 Vario COM III
• 930 Vario COM III
• 933 Vario COM III
• 936 Vario COM III
• 300 Vario series
• 400 Vario series
• 700 Vario series
• 800 Vario series
• 900 Vario series

1. 1

   Test the physical operation of the 750/540E rear PTO speed selector button on the armrest to see if it is mechanically stuck, damaged, or unresponsive.

2. 2

   Check if other buttons on the Multifunction Armrest are working. If multiple buttons are failing, the issue may be a broader CAN bus communication failure or a power supply issue to the entire MFA.

3. 3

   Inspect the wiring harness, connectors, and pins connecting the MFA to the tractor's main cab harness for signs of chafing, corrosion, or loose connections.

4. 4

   Check the fuses supplying power to the armrest control modules.

1. 1

   Park the tractor safely, turn off the ignition, and disconnect the battery to prevent electrical shorts during disassembly.

   Park the tractor safely, turn off the ignition, and disconnect the battery to prevent electrical shorts during disassembly.

2. 2

   Carefully remove the cover panels of the Multifunction Armrest (MFA) to access the internal switch modules and circuit boards.

   Carefully remove the cover panels of the Multifunction Armrest (MFA) to access the internal switch modules and circuit boards.

3. 3

   Locate the specific switch module for the rear PTO speed selection.

   Locate the specific switch module for the rear PTO speed selection.

4. 4

   Inspect the localized wiring and ribbon cables inside the armrest for breaks or unseated connectors.

   Inspect the localized wiring and ribbon cables inside the armrest for breaks or unseated connectors.

5. 5

   Test the 750/540E button for electrical continuity. If the switch fails the continuity test or the internal communication board is burnt/damaged, the switch or the armrest unit must be replaced.

   Test the 750/540E button for electrical continuity. If the switch fails the continuity test or the internal communication board is burnt/damaged, the switch or the armrest unit must be replaced.

6. 6

   Install the new switch or replacement MFA unit and reassemble the armrest housing.

   Install the new switch or replacement MFA unit and reassemble the armrest housing.

7. 7

   Reconnect the battery and turn on the ignition.

   Reconnect the battery and turn on the ignition.

8. 8

   Access the tractor's terminal to clear the stored 06.1.B7 fault code from the memory.

   Access the tractor's terminal to clear the stored 06.1.B7 fault code from the memory.

9. 9

   Test the rear PTO speed selector to confirm the 750/540E speed engages properly and no new codes are generated.

   Test the rear PTO speed selector to confirm the 750/540E speed engages properly and no new codes are generated.