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

The control module is detecting an incorrect, out-of-range, or missing electrical signal voltage coming from the hand throttle potentiometer (sensor) located on the tractor's armrest console.

• 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
• 4700 Series
• 4707
• 4708
• 4709
• 4710
• 5600 Series
• 5700 Series
• 5608-5613
• 5709-5713
• 6400 Series
• 6600 Series
• 6700 Series
• 6445-6499
• 6612-6616
• 6712S-6718S
• 7400 Series
• 7600 Series
• 7700 Series
• 7465-7499
• 7614-7626
• 7714-7726
• 8400 Series
• 8600 Series
• 8700 Series
• 8450-8480
• 8650-8690
• 8727-8740

1. 1

   Visual Inspection: Inspect the wiring harness and the connector leading to the hand throttle potentiometer inside the armrest for chafing, pinched wires, or loose pins.

2. 2

   Voltage Test: Using a multimeter, verify that the potentiometer is receiving the correct 5V reference voltage and ground from the MFA controller.

3. 3

   Signal Sweep Test: Back-probe the signal wire and slowly move the hand throttle from the minimum to the maximum position. The voltage should scale smoothly without dropping out or spiking. If there are 'dead spots,' the potentiometer is internally faulty.

4. 4

   Calibration Check: Sometimes the sensor simply loses its learned limits. Attempt to recalibrate the hand throttle via the tractor's terminal (often accessed via calibration code 4002 for the hand throttle).

1. 1

   Power Down

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

2. 2

   Access the Sensor

   Carefully remove the trim panels on the Multifunction Armrest (MFA) to expose the internal hand throttle linkage and sensor assembly.

3. 3

   Remove the Faulty Sensor

   Disconnect the electrical harness from the hand throttle potentiometer. Remove the retaining screws or clips holding the sensor to the throttle lever mechanism.

4. 4

   Install the New Part

   Mount the new potentiometer in the exact same orientation. Secure the fasteners and plug in the electrical connector.

5. 5

   Reassemble

   Reinstall the armrest trim panels and reconnect the battery.

6. 6

   Calibrate the New Sensor

   Turn the ignition ON. You must calibrate the new sensor so the MFA knows the physical limits of the new potentiometer. Enter the tractor's diagnostic/calibration menu (Calibration 4002). The screen will prompt you to move the hand throttle to the maximum position and press 'Return/OK' to confirm, then move it to the minimum position and confirm.

7. 7

   Clear Codes

   Clear the 03.00.9D fault code from the system and test the throttle operation.