Massey Ferguson 03.02.A2 – MFA (Multifunction Armrest): Issue With Speed Control Lever Position Sensor On Armrest Signal Voltage (MFA)

This indicates a circuit or sensor failure where the voltage signal coming from the speed control lever's position sensor is either out of the expected range (too high/too low), erratic, or completely missing.

• 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
• 5S Series
• 5700 S / SL Series
• 6700 S Series
• 7700 S Series
• 8700 S Series

1. 1

   Visual Inspection: Remove the armrest trim and inspect the wiring harness leading to the speed control lever position sensor. Look for chafed wires, pinched cables, or disconnected plugs.

2. 2

   Connector Check: Disconnect the sensor and inspect the pins for corrosion, moisture, or pushed-back terminals.

3. 3

   Voltage Testing: Using a multimeter, verify that the sensor is receiving the correct reference voltage (typically 5V) and has a solid ground from the MFA module.

4. 4

   Signal Sweep Test: Using a diagnostic tool (like AGCO EDT or Jaltest) or a multimeter, monitor the sensor's signal voltage while slowly moving the speed control lever through its full range of motion. The voltage should change smoothly without dropping out or spiking. If the voltage is stuck or erratic, the sensor is faulty.

5. 5

   CAN Bus Verification: Ensure there are no accompanying TECU or CAN bus communication codes (such as 03.03.19), which might indicate a broader network issue rather than an isolated sensor failure.

1. 1

   Power Down

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

2. 2

   Access the Sensor

   Carefully remove the plastic housing/trim of the Multifunction Armrest to expose the internal lever mechanisms and circuit boards.

3. 3

   Remove the Sensor

   Locate the speed control lever position sensor. Disconnect its electrical harness. Depending on the specific armrest revision, the sensor may be held in place by small Torx screws or retaining clips. Remove the fasteners and extract the sensor. (Note: On some assemblies, the sensor is integrated into the lever base, requiring replacement of the sub-assembly).

4. 4

   Install the New Part

   Mount the new sensor (or lever assembly) into position and secure the fasteners. Reconnect the electrical harness, ensuring it clicks into place.

5. 5

   Reassembly

   Reinstall the armrest trim and covers.

6. 6

   Calibration

   Reconnect the battery. Connect a diagnostic tool to the tractor's diagnostic port. Clear the 03.02.A2 fault code. You will likely need to run a lever calibration routine via the diagnostic software or the Datatronic terminal so the MFA learns the new sensor's minimum, maximum, and neutral voltage values.