Massey Ferguson 03.00.9E – MFA (Multifunction Armrest): Issue With Hand Throttle On Arm Rest Signal Voltage (MFA)

The electronic control system has detected an electrical signal from the hand throttle potentiometer that is outside of the expected voltage parameters (either too high or too low). When this signal drops out, shorts, or spikes, the tractor will log this code and may disable the armrest controls or default to foot-pedal throttle operation only.

• 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
• 6616 Dyna VT
• 7614
• 7615
• 7616
• 7618
• 7619
• 7620
• 7622
• 7624
• 7626
• 8650
• 8670
• 8700 Datatronic 5

1. 1

   Inspect the wiring harness routing from the hand throttle lever inside the armrest console to the MFA module. Look for chafed wires, pinched harnesses, or disconnected plugs.

2. 2

   Disconnect the hand throttle potentiometer. Check the pins for corrosion, moisture, or poor terminal tension.

3. 3

   Using a multimeter, verify that the potentiometer is receiving the correct reference voltage (typically 5V or 8.5V depending on the exact model) and has a solid ground from the MFA.

4. 4

   Back-probe the signal wire. Slowly move the hand throttle lever from the idle position to maximum RPM. The voltage should sweep smoothly without any dropouts or spikes. If the voltage drops to 0V or jumps erratically, the potentiometer has an internal failure.

1. 1

   Power Down

   Turn off the tractor ignition and disconnect the negative battery cable to prevent electrical shorts.

2. 2

   Access the Armrest Internals

   Remove the retaining screws securing the top cover or side trim of the Multifunction Armrest console to expose the internal control linkages.

3. 3

   Remove the Faulty Sensor

   Locate the hand throttle lever assembly. Disconnect the electrical connector from the throttle potentiometer.

4. 4

   Dismount the Potentiometer

   Remove the mounting hardware (screws/washers) securing the potentiometer to the throttle lever shaft.

5. 5

   Install the New Part

   Fit the replacement potentiometer onto the shaft, ensuring the alignment tangs/slots match up correctly so the sensor reads the full physical sweep of the lever. Secure it with the mounting hardware.

6. 6

   Reassembly

   Reconnect the electrical harness. Reinstall the armrest covers and trim.

7. 7

   Calibration

   Reconnect the battery. Turn the ignition on. You will likely need to use the tractor's SIS (Setup and Information Screen) or a dealer diagnostic tool (like AGCO EDT) to clear the inactive 03.00.9E fault code and perform a calibration routine for the new hand throttle potentiometer so the MFA learns the new minimum and maximum voltage values.