Massey Ferguson 3.X.1A – MFA (Multifunction Armrest): CAN Bus Message From Spool Valve Controls 1 And 2 On Arm Rest (MFA)

CAN bus communication failure or missing message between the electronic fingertip spool valve controls (specifically for valves 1 and 2) and the armrest control module.

• 5710SL
• 5711SL
• 5712SL
• 5713SL
• T4
• 5700 S / SL Series
• 6600 Series
• 6700 S Series
• 7600 Series
• 7700 / 7700 S Series
• 8600 Series
• 8700 / 8700 S Series

1. 1

   Check the internal armrest wiring harness that connects the fingertip spool valve control module (micro-joystick/rockers) to the main MFA controller. Look for pinched wires, chafing, or loose connector pins.

2. 2

   Ensure the fingertip control module is receiving proper voltage and has a solid ground connection. A loss of power to the switch module will cause it to drop off the CAN bus.

3. 3

   Check for other active CAN bus fault codes (e.g., codes starting with 'U' or other MFA communication codes). If multiple armrest components are offline, the issue is likely the main armrest CAN harness rather than the specific spool valve switch.

4. 4

   Inspect the fingertip linear modules (rockers) for physical damage, sticking, or liquid intrusion (spilled drinks on the armrest are a common cause of switch failure).

1. 1

   Disconnect Power

   Turn off the tractor and disconnect the battery to prevent electrical shorts while working inside the armrest.

2. 2

   Disassemble the Armrest

   Carefully remove the top cover/trim of the Command Control Armrest to access the internal modules and wiring.

3. 3

   Inspect and Clean

   Disconnect the harness from the fingertip spool valve control module for valves 1 and 2. Inspect the pins for corrosion or spread terminals. Clean with electrical contact cleaner and reconnect to see if the connection was simply loose.

4. 4

   Test the Harness

   Use a multimeter to verify continuity on the CAN High and CAN Low wires between the fingertip module connector and the main MFA board.

5. 5

   Replace the Module

   If the wiring is intact, power/ground is present, and the code persists, the fingertip control module itself has failed internally and must be replaced. Remove the retaining screws, swap in the new module, and reconnect the harness.

6. 6

   Calibrate the New Component

   Reassemble the armrest and power on the tractor. You must use a compatible diagnostic tool (such as AGCO EDT or Jaltest) to perform the 'calibration of the spool valve control lever' in the MFA system so the armrest recognizes the new module's parameters.

7. 7

   Clear Codes

   Clear the fault codes and test the hydraulic spool valves for proper operation.