Massey Ferguson 03.00.A2 – MFA (Multi-Function Armrest): Issue With Speed Control Lever Position Sensor On Armrest Signal Voltage (MFA)

The system is detecting an irregular, missing, or out-of-range voltage signal from the potentiometer or Hall-effect sensor that monitors the physical position of the ground speed control lever (often part of the Multipad joystick) on the tractor's armrest.

• 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
• 5609
• 5610
• 5611
• 5612
• 5613
• 7614
• 7615
• 7616
• 7618
• 7619
• 7620
• 7622
• 7624
• 7626

1. 1

   Check the supply voltage going to the ground speed control lever position potentiometer (typically around 8.5 Volts or 5V on some sensor variants).

2. 2

   Inspect the wiring harness running from the MFA module to the speed control lever potentiometer for chafing, interruptions (open circuits), or shorts to ground/power.

3. 3

   Using a multimeter or a diagnostic tool, monitor the signal voltage while slowly moving the speed control lever through its full range of motion to ensure the voltage changes smoothly without dropping out or spiking.

4. 4

   Disconnect and inspect the multi-pin connectors at both the sensor and the MFA module for bent pins, corrosion, or moisture ingress.

1. 1

   Power Down

   Turn off the tractor and disconnect the battery ground cable to prevent electrical spikes during repair.

2. 2

   Access the Sensor

   Remove the protective covers/trim on the Multi-Function Armrest to expose the base of the Multipad joystick and the speed control lever assembly.

3. 3

   Harness Repair

   If the diagnostic checks revealed a broken wire in the armrest loom, repair the wiring using appropriate heat-shrink connectors and re-test.

4. 4

   Sensor/Joystick Replacement

   If the wiring is intact but the sensor failed the sweep test, the sensor must be replaced. Note: On many modern setups, the sensor is integrated into the joystick assembly, requiring replacement of the joystick unit or sub-assembly.

5. 5

   Reassembly

   Plug the new sensor/joystick into the MFA harness and reassemble the armrest trim.

6. 6

   Calibration

   Reconnect the battery and perform a joystick/speed control lever calibration using a compatible diagnostic tool (e.g., Jaltest or AGCO EDT) so the MFA module learns the new sensor's minimum, maximum, and neutral voltage values.

7. 7

   Clear Codes

   Clear the 03.00.A2 fault code from the MFA memory and test drive the tractor to ensure normal transmission speed control.