Massey Ferguson 03.01.A2 – MFA (Multi-Function Armrest): Issue With Speed Control Lever Position Sensor On Armrest Signal Voltage

The electronic control system has detected an abnormal signal voltage (either too high, too low, or erratic) coming from the position sensor located inside the speed control lever (often integrated into the main armrest joystick).

• 7724S
• 5712SL
• 7722
• 7722S
• 5713SL
• 7720S
• 7716
• 7718
• T4
• 7715
• 5710SL
• 7726
• 7726S
• 5711SL
• 7718S
• 7719
• 7714
• 7716S
• 7720
• Tier 4 (2015-2021)
• 7715S
• 7724
• 4707
• 4708
• 4709
• 4710
• 5608–5613
• 5710SL–5713SL
• 5709S–5713S
• 6613–6616
• 6713S–6718S
• 7614–7626
• 7714–7726
• 7715S–7719S
• 8727S–8740S

1. 1

   Connect a compatible diagnostic tool to monitor live voltage data for the Speed Control Lever Position Sensor while moving the lever through its full range of motion, watching for dropouts, spikes, or dead spots.

2. 2

   Remove the armrest trim and inspect the wiring harness connecting the joystick/speed lever to the MFA circuit board for pinched wires, chafing, or loose connector pins.

3. 3

   Disconnect the sensor and use a multimeter to verify that the MFA module is supplying the correct 5V reference voltage and a solid ground to the sensor.

4. 4

   If the reference voltage and ground are good but the signal voltage is out of range or erratic during physical movement, conclude that the sensor or joystick assembly has failed internally.

1. 1

   Power Down

   Turn off the tractor and disconnect the negative battery cable to prevent electrical shorts while working near the MFA circuit boards.

2. 2

   Access the Armrest Internals

   Carefully remove the plastic covers and trim pieces from the Multi-Function Armrest to expose the joystick assembly and the MFA controller board.

3. 3

   Disconnect the Lever

   Unplug the electrical connector linking the speed control lever/joystick to the MFA module.

4. 4

   Remove the Assembly

   Remove the retaining screws holding the joystick/speed control lever assembly in place. (Note: On most modern Massey Ferguson armrests, the position sensor is not serviced separately; the entire joystick element must be replaced).

5. 5

   Install the New Part

   Seat the new joystick/lever assembly into the armrest and secure it with the retaining screws. Reconnect the electrical harness.

6. 6

   Reassemble

   Reinstall the armrest covers and trim. Reconnect the battery.

7. 7

   Calibration

   Connect your diagnostic tool. Clear the 03.01.A2 fault code. You must perform a joystick/speed lever calibration routine within the MFA module software so the system can learn the new sensor's minimum, maximum, and neutral voltage values.